Assist in creating a DIY Guide to Installing Grid Tied Solar on your Home. - Page 1
Forum section: electronics / general

author: DougSpindler
author_rank: Super Contributor
timestamp: April 16, 2018, 10:46:39 pm
content: I live in California in the San Francisco Bay Area. I've been looking into installing solar for a couple of years now but have very little confidence in any of the companies who install solar. I consume 10,000 kWhrs of electricity per year and have received quotes from $15,000 for 6 panels to $45,000 for 42 panels to "perfect" solar system for my house. Let’s just say I’m feed up with the bull-shit I’m being told by the uninformed “well trained, state licensed solar experts”.As I research the cost of installing solar, the more I realize what a cash cow this is for the solar sales folks. I have no problem paying for services, but when I know more than they do, then I have a problem.I'd like to create this post to help me and others install a solar system on their home. Our local power company, PG&E has what has to be the most expensive rates in all of the United States if not the world. For the rate plan I am on I’m paying at times $0.45 kWhr. And other PGE&E customers are paying up to $0.85 kWhr. At $0.45 kWhr let’s say I a really motivated right now.My local power companyPower company: PG&E. Power company offers 9 different rate plans for residential customers.Tiered, straight Time of Use and Tired Time of Use. Customers must pick one of the 9 rate plans and can’t change it for 1 year.Rate plan I am on is straight Time of Use. I am charged six different rates depending on the time of day and day of the year. Rates range from $0.12 to $0.45. In one day I can be charged 5 different rates.In the past the agreement with the power company was if customers solar system over produced 1 kWhr it would be loaned to the power company until the customer needed it. And when the customer needed to consume a KWhr they could cash in on that loan and get it back at no cost. At the end of the year there would be an annual true up. Customers who had credits with the power company would receive $0.02 kWhr as a credit on their bill.That was in the past. The way our power company is doing this is based on fair market value of the kWHr when it is purchased or “sold” to the power company. This means when the power company is charging $0.45 kWhr for electricity I can “sell” any extra kWhrs to the power company at $0.45. But then later in the day when the power company is charging $0.12 I can “buy” back the kWhr I “sold” to them at $0.45 for just $0.12. None of the solar companies I have talked to understand this let alone know how to design for Time of Use customers.I use 10,000 kWhrs annually. Under ideal conditions if I could “sell” all the power I produce at $0.45 and buy the power back at $0.12. This means when it comes to sizing a solar system for my house I only need a system which generates about 3,000 kWhrs per year (which I sell to the power company at $0.45) to cover the 10,000 kWhrs consume every year at $0.12.

author: DougSpindler
author_rank: Super Contributor
timestamp: April 16, 2018, 11:09:09 pm
content: My situationI use about 10,000 kWhrs of electricity per year. But let’s call it 12,000 for future growth.I am on a straight Time of Use Rate plan, there is no tiering.Power company has winter rates, and summer rates. Off-peak, partial-peak and peak.Winter rates are $.012, $0.22 and $0.32 kWhr. Summer rates $.012, $0.24 and $0.45 kWhrM-F there the rate changes 5 times per day. Weekends we have 3.We have net metering. We don’t trade kwhrs with the power company. Extra kWhrs are sold to the power company at the time produces for an energy credit in $ $. So for every kWhr I “sell”/receive a credit for with the power company I can use that $$$ energy credit to “buy” kWhr back at a lower rate.Peak hours begin at 2:00pm M-F.House faces 190 – Should be ideal for solar production. I have an east and west facing roof surface I could use.At 38 north LatitudeRoof is in full sun all year. No trees or obstructions.My electricity usage has been consistent.Very little during partial-peak hrs (M-F mornings – 2:00pm)And very little during peak hrs (2:00 pm)Most of my electricity (65%)consumption is during off-peak hours

author: ez24
author_rank: Super Contributor
timestamp: April 16, 2018, 11:10:20 pm
content: Not sure if there is a question here. Mine is - are you going to install it yourself? How about permits? I know if you are going to "tie" in, you will need permits. That alone might make it worth it to pay someone else. There might be a solar permit business?With 42 panels you can do a lot of things, like take up pottery as a hobby (electric kilns). A big smile on your face when you open your electric bill.Maybe start a protest by setting up electric heaters in your front yard (against the tiers).

author: DougSpindler
author_rank: Super Contributor
timestamp: April 16, 2018, 11:18:42 pm
content: Here's my first question... Which direction should the solar panels be facing.I know for maximum solar panel production in kHrs one would favor a south orientation but that's no longer the best design for Time of Use customers.I'm thinking west is the preferred direction to maximize energy credits inwith my power company as they "pay"/credit either 2 or 375 times more for kWhrs produced during peak hours. I would think with four west facing panels I would have the same benefit as 6 or 7 panels facing south and 8 facing east.Any thoughts?

author: ez24
author_rank: Super Contributor
timestamp: April 16, 2018, 11:32:07 pm
content: Quote from: DougSpindler on April 16, 2018, 11:18:42 pmYou can "preview" and correct spelling errors (they are underlined in red) and format errors. (the dollar signs showed up as "math error" - never saw this before).There are many solar installation apps (both Apple and Android). My friend used one to predict shadows from trees. I bet you can find one on tier pricing. But anyway this is interesting.

author: DougSpindler
author_rank: Super Contributor
timestamp: April 16, 2018, 11:36:25 pm
content: Quote from: ez24 on April 16, 2018, 11:10:20 pmI plan to install myself.Our county has speed permitting. It's $160 and the permit is 9 pages. Planning on doing that myself.One I have county approval I have to get permission from the power company to operate. Power company has made that quite easy.I have 3 breaker panels. Can tie in to any one of them.Local code does not require a master discontent at service entrance.New 2018 building codes changed the setbacks to 18 “in the US. In the past there was I think a 3-foot setback on all side was required. I need to verify but I think the new codes allow for 18" on all sides as long as there is one 3 foot set-back on an adjoining roof surface as in across a valley.

author: Nusa
author_rank: Super Contributor
timestamp: April 16, 2018, 11:53:06 pm
content: You're mostly talking about details that are very specific to the country and state that you live in. We can discuss that if you want, but recognize that this forum has a significant international audience, and solar situations around the world may be very different.However, it happens I'm in California and am somewhat familiar with said rules. My main observation is that rules about net metering are subject to change, and it's quite likely that they will change in coming years. There's certainly enough lobbying going on.In my opinion, you should justify getting solar solely based on power you can use or store yourself(batteries or thermal) and the resulting reduction in purchases from the grid. Selling power back to the grid should be considered a bonus, but don't count on making much money doing so, long-term.

author: DougSpindler
author_rank: Super Contributor
timestamp: April 17, 2018, 02:11:12 am
content: If anyone know of an iPad or iPhone solar app to produce estimated yearly production values I would be interested.PG&E Toolkit (Apple and PG&E customers only. Logs into your PG&E account, downloads your actual usage and shows you what you are paying every month for electricity. PG&E has 9 different rate plans for customers and PG&E Tool Kit shows price comparison.This one app taught me a lot about how I use electricity and how power companies bill for electricity.5 Stars from me. (But unfortunately, the API with the power company is having issues.)https://itunes.apple.com/us/app/my-pg-e-toolkit/id733009344?mt=8If there are any App authors out there look at this app for ideas.Other apps I have tried to use includeSolarMeter (Apple app) looks good but haven’t figured out how to fully use it.PV Optimizer (Apple apps) Looks good, but not exactly that helpful for designing residential solar.

author: mtdoc
author_rank: Super Contributor
timestamp: April 17, 2018, 03:08:32 am
content: Quote from: DougSpindler on April 17, 2018, 02:11:12 amThis is better than any App I’m aware of:PV Watts calculatorfrom the NREL.

author: DougSpindler
author_rank: Super Contributor
timestamp: April 17, 2018, 03:47:22 am
content: Quote from: Nusa on April 16, 2018, 11:53:06 pmI understand.I thought instead of making this all about me, I would try to make this a bit more general, so it would help others.QuoteIt is far more cost effective to "sell" the extra electricity to PG&E and get energy credits and buy the power back with those energy credits when the cost of electricity is lower.One could do the same thing with the battery units without even installing solar panels. Change when rates are low, and sell to the power company when rates are higher. Rate plan I'm on I would get a 375% advantage in doing so.But I learned from Dave battery units are very inefficient. In charging and discharging the batteries 40% of the electrical energy is lost as heat.

author: DougSpindler
author_rank: Super Contributor
timestamp: April 17, 2018, 03:49:18 am
content: Quote from: mtdoc on April 17, 2018, 03:08:32 amHave you used PV Watts to design a solar system?

author: ez24
author_rank: Super Contributor
timestamp: April 17, 2018, 04:44:19 am
content: Quote from: DougSpindler on April 17, 2018, 03:49:18 amTake a look at their other program which seems to take $ into account:https://sam.nrel.gov/

author: mtdoc
author_rank: Super Contributor
timestamp: April 17, 2018, 04:48:18 am
content: Quote from: DougSpindler on April 17, 2018, 03:49:18 amI’ve used it to confirm the best orientation and tilt for array installation and I’ve used it to compare the benefits of a one or two axis tracker to a larger fixed array. The later was a bigger deal when panels were more expensive. Now that panels are cheap, the answer is almost always a bigger array or multiple arrays with different orientations.

author: f4eru
author_rank: Super Contributor
timestamp: April 17, 2018, 10:28:55 am
content: Quote from: DougSpindler on April 17, 2018, 03:47:22 am60% cycle efficiency ? That's very very bad. Is it NiMh ?Modern Li batteries have 95% cycle efficiency, while lead acid are 85% typically

author: sokoloff
author_rank: Super Contributor
timestamp: April 17, 2018, 10:52:02 am
content: Quote from: f4eru on April 17, 2018, 10:28:55 amThey don't have 95% efficiency when you consider them as a system (considering charging voltage conversions, coolant pumps, and any other support systems). I'm pretty sure my car charging loses more than 10% on a full-cycle basis.

author: DougSpindler
author_rank: Super Contributor
timestamp: April 17, 2018, 04:13:15 pm
content: Quote from: f4eru on April 17, 2018, 10:28:55 amDave talking about lead/'acid storage cells. Problem with Li and NiMh is the short life span. Yes they might be more efficient, but they don't seem to last for more than a few years with daily charging/discharging.

author: DougSpindler
author_rank: Super Contributor
timestamp: April 17, 2018, 05:59:41 pm
content: Solar panels, Mono or Poly?From what I've been reading and what Dave said in his video seems it doesn't seem to mater much.Not sure that brand name makes a difference either. Panels for residential use (at this time) produce in the 275 to 325 watt range.My thinking is to go for "best" price. Or are there other factors I should be considering. I'm also thinking these panels are held in with four bolts and have two connection wires if on goes bad it's a simple mater to replace it with another one. And chances are prices will continue to decrease as production increases so a replacement will cost less and produce more.I think solar shingles and anything else other than mono or poly are not worth considering at this time.Inverters, micro-inverters and optimizersWhen I first looked at solar I was told to use an inverter. Then I was told micro-inverters were better. And now when I ask people I'm being told inverters but add in an optimizer.My roof is in full sun. I'm thinking I don't need an optimizer, but then I read in a post optimizers allow for the monitoring if each solar panel instead of the just the entire system. I would think this would be a plus if I don't have or pay for a monitoring service.WiringMy understanding is the the wire guage and type of is different if you use an inverter, micro-inverters and optimizers. Heve not really found any good informaiotn to figure out what to use. I'm sure there are advantages and disadvantages for each. Just not sure what they are.

author: metrologist
author_rank: Super Contributor
timestamp: April 17, 2018, 06:42:44 pm
content: I'm not sure how you're planning to work the numbers in your favor, unless you are able to shift all 27kWh daily use to off peak time.If you run some numbers on battery cost and lifespan, you will see that batteries can cost as much as a standard electric rate, so you loose with self storage.I agree with a grid tied system that is optimized for energy production. I believe your area has a solar insolation rating around 5, so you could expect about 1500WHr/day out of a 300W panel.

author: DougSpindler
author_rank: Super Contributor
timestamp: April 17, 2018, 08:31:13 pm
content: Quote from: metrologist on April 17, 2018, 06:42:44 pmThanks. If the 1500WHr/day is correct I need to figure out solar production values to energy credits with the power company.I'm attaching a typical daily usage report from the PG&E Tookit app for a 24 hr period on a week day.If you look you will see I use most of my electricity when rates are at $0.12 kWhr. Durning the day when the power compny will credit me for a kWhr they will "pay" either $0.24 or $0.45 kWhr. I'm thinking not guessing I since I would accrue so many enegy credits in the summre months when the cost per kWhr is $0.13 higher in the winter I would only need a system which would produce about 5,000 kWhrs per year or about half of the kWhrs I actulay consume every year to (near) zero out my bill with the power compnay.I beleive you are correct I am in the 5 zone.Not following your units. 1500WHr/dayPlease correct my math if it's incorrect.If I use 12.000 kHrs in a year would dividing by 1500WHr/day be the number of panels I would need to produce 12,000? That woudl be 8. But that doesn't sound right. Or do I need to multiply the 8 buy 5.5 hrs of sun per day which would mean I would need 40 panles? That doesn't seem right to me either.

author: metrologist
author_rank: Super Contributor
timestamp: April 17, 2018, 09:04:48 pm
content: The insolence number is an annual average. It is basically telling you how many hours a panel will produce maximum output. That was 1500WHr per panel per day in your area. I am just considering averages for all your numbers, so 12,000kWHr per year is about 32kWHr/day, and it would take ~21 panels to produce that amount of power (32kWHr/300Wx5). You will have excess in the summer and not enough during the winter.Since your use is primarily off-peak, setting up for maximum output would be ideal. You might be able to get a little more in the translation if you split your array to favor both morning and evening, but I suspect that producing more during peak sun hours @ mid peak rate would pay more overall than producing less @ peak rate.BTW, aren't the higher rates you pay ($0.45) because of your use bumping you into a higher tier? I know you said you are on TOU plan, but I did not think PG&E had any base rate that high. I'm also not familiar with PG&E solar energy buyback program, but I would be surprised if they paid that much for residential solar production.

author: woody
author_rank: Frequent Contributor
timestamp: April 17, 2018, 09:39:40 pm
content: A couple of quick remarks:- West (or east or worse still, north) facing panels make less electricity than south facing panels in the northern hemisphere. I am not sure how these credits work out where you are but in my country one would be crazy to mount panels west if south was an option.- Find the kWh/kWp factor for your location. This is based on a panel that faces in the ideal direction, at the ideal elevation that gets the average sun hours for the area. As an example, on my latitude (52 deg.), for a south facing, 35 degree elevated panel that factor is 0.85 kWh/kWp. With this factor you can calculate the total kWp you need. For instance, when I want to generate 6000 kWh I need 6000/0.85 = 7058 kWp. If I use 300Wp panels I would need 7058 / 300 = 24 panels. Factors like dirt (soot/moss/birdshit/leaves/snow), shading, less than ideal placement, inverter efficiency, panel age etc. all negatively influence the output of solar panels.- Advantages of microinverters: No high DC voltages on your roof. MPPT per panel, so superb compaired to string inverters when shadow is an issue. Better monitoring on a per-panel basis. Supposedly longest life (YMMV). No noisy central inverter that needs to be replaced maybe twice during the life of the panels.- Disadvantages of microinverters: More expensive. Difficult to replace if one goes down because they are under the panels and on your roof. Slightly lower total efficiency.- Mono-crystalline panels look better.- Battery solutions in a grid-connected situation are unaffordable. Last time I did the calculation the price of a saved-and-recovered kWh from a Tesla powerwall was €0,55 cents ex. the cost of the kWh itself. Or nearly three times the price of a kWh straight from the grid. Might be better when the price of a powerwall plummets.

author: DougSpindler
author_rank: Super Contributor
timestamp: April 18, 2018, 04:09:52 am
content: Quote from: metrologist on April 17, 2018, 09:04:48 pmThanks for explaining.I think it makes little sense to have any east facing panels. Power company would only pay $0.12 or $0.24 kWhr. West facing would pay $0.24 or $0.45 when the sun is at the same angle.This whole thing of over producing to earn energy credits in $$$ and then using those credits to buy the electricity back makes this complicated.BTW, aren't the higher rates you pay ($0.45) because of your use bumping you into a higher tier? No.I am on a stright Time of Use, no tiering rate plan. Every day durning the summer months I have to buy electricy for $0.45. PG&E has two rate plans like this.The 7 other 7 rate plans all have tiering. But only one rate plan (that will be disconituned end of this year) is stright tiering. The ohter 6 rate plans are all Time of Use with Tiering. I belive those rate plans in the highest tier are not more than $0.36 kWHr.I have to thank the folks who wrote the PG&E Toolkit app as it show for the amount of electricy I use how much PG&E would charge me for all 9 rate plans. Almost every month the rate plan I am on works out to be the most cost effective for me. The Time of Use Tiered rate plans are always more expensive for me.PG&E appears to be the leader in complicated rate sturctures for consumers. I suspect other power companies will follow. This is only possible with Smartmeters.

author: sokoloff
author_rank: Super Contributor
timestamp: April 18, 2018, 12:12:54 pm
content: Quote from: DougSpindler on April 18, 2018, 04:09:52 amYou also need to factor in some change risk. You’re installing panels for 25+ years. The sun will keep following the same path in the sky that whole time. The billing and credit arrangements with your local power company are not nearly as stable.

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: April 18, 2018, 03:01:59 pm
content: I do not think that PG&E or any power company is going to let you buy low & sell high , if there is a chance of doing that , it will change fast .You must be missing something , thinks that ?Seems to be similar thinking with facing panels ?

author: DougSpindler
author_rank: Super Contributor
timestamp: April 18, 2018, 03:55:09 pm
content: Quote from: KD0CAC John on April 18, 2018, 03:01:59 pmNope.Found this on PG&E’s web site.“Monthly statement: Each month, your PG&E Energy Statement shows the amount due for that billing period including monthly minimum delivery charges. The statement also shows a summary of your year-to-date solar charges and credits and how you are tracking towards True-Up.”Every “solar expert” I’ve talked to tells me the same thing. There have been four times when the solar guy has called PG&E with me and the PG&E rep tells the solar guy he has it all wrong. And the solr guy responds by saying the rep doesn’t know what they are saying as in trying to “trick” me. They also say the web site is wrong. The video is wrong and the wording in my rate plan contract is wrong too.Thinking maybe they might be right, I’ve called PG&E on my own and spoke to other reps, who are well trained and quite knowledgeable all tell me the same thing as what’s in the video.All of the solar companies tell me same thing you are saying, that I have it all wrong. I have called PG&E at least 6 different times. Every time PG&E tells me the solar guys have it wrong.I’ts in the rate plan contract Ihave with PG&E.I’t’s on PG$E’s web site.And they made a video years ago that say the same thing.In the video they have example houses. The third one at about (:40 seconds) is for Time of Use.They clearly if you overproduce you can export to the grid rates are higher and use/buy back when prices are lower. Notice they use the word prices, and not kWhrs.What they don’t say in the video is if you have any roll over extra energy $$$ credits. At the end of 12 months you forfeit the all of the energy credits and in some cases PG&E might give you $0.02 on the dollar.https://youtu.be/5yVgPrhvwyc

author: DougSpindler
author_rank: Super Contributor
timestamp: April 18, 2018, 04:14:42 pm
content: Quote from: sokoloff on April 18, 2018, 12:12:54 pmYes, but PG&E has too many solar customers producing electricty during mid day when solar production is at it’s greatest. They are paying at those times because they don’t need it. Same is true with late morning. Then don’t need the solar generated electricity so they pay even less.What PG&E is doing is raising the rates they are paying for solar electricity when they need it. Early afternoon into early evening.). One rate plan has PG&E paying $0.85 kWhr for solar generated electricty exported to them.If anything PG&E will continue to increase the amount of money they charge or will credit for kWhrs sold to them mid-afternoon or when the sun is to the west.There is no reason the increase off peak rates. At those times PG&E has more electricty than is in demand by customers.PG&E is telling customers install panels on a west facing roof before installing on south facing roof.

author: ez24
author_rank: Super Contributor
timestamp: April 18, 2018, 06:06:06 pm
content: Quote from: sokoloff on April 18, 2018, 12:12:54 pmI have a friend who went through all the shit you are going through. Tiers and buy-backs calculations up the ying-yang. He would brag about the money all the time. Then utility company (in So Calif) changed the rules and now he will not even talk about it (ie the buy-back is now worth less than $2 a year and he has a lot of panels ).He also went with the local controller that is on each panel. After the warranty expired, one panel went out and he was able to tell which one (he checks the software daily) and went up on the roof and replaced it. I helped him lift the new panel on the roof. I just cannot understand why - his income is over $1000 a day and at 70 he was on his roof replacing panels? Don't get so crazy.

author: fourtytwo42
author_rank: Super Contributor
timestamp: April 18, 2018, 07:26:32 pm
content: May be you have to decide if you are doing this as a money making excercise or not. In the UK you only get subsidy if the whole installation is done by a "professional installer" and of course that get's you involved in all sorts of crazy calculations as well as crystal ball gazing.Personally I installed my subsidy free DIY system in part to help the enviroment, in part to further reduce my "grid" dependancy and in my case to reduce both my oil and electricity bills. I don't have to fret whatever about subsidy rates and I already know my payback times worst caseI would be very wary of spending a lot of money and expecting to get it back again in a hurry!

author: DougSpindler
author_rank: Super Contributor
timestamp: April 19, 2018, 06:23:51 am
content: I think you are misunderstanding what’s going on with PG&E. All customers by the end of this year are required to be on a TOU rate plan. One can not make money selling electricty to PG&E. But what we all have to do is “sell” the excess we produce at market rate to PG&E to receive energy credits which are measured in dollars. At the end of 12 month any energy credits dollars are given to PG&E for free. There are no roll over energy dollar credits after a year.In the past solar customers who prodced excess kWhrs would receive credits based on kWhrs, not the value of the kWhr. Customers were trading kHrs not the value of the kWhr at the time it was produced or purchased back. Those days are over for us.The challenge solar companies and potential customers have right now is figuring out the correct size system to purchase. Based on my actual usage of 10,000 kWhrs per year if I were to purchase a solar system which produced 10,000 kWhrs per year in 25 years I will have given over $130,000 of free electricty to the power company (PG&E) for free, I also would have paid two to three times as much for a solar system. Makes no sense to me to spend $20,000 to $30,000 for a solar system when a system costing me $10,000 would provide all the electricty can use.I have a feeling PG&E has figured this out and once existing solar customers are switched onto the new rate plans next year many will be grossly over producing electricty and having to give that electricity away for free to the power company.Many existing PG&E customers who have solar panels which were designed to off set 100% of the kWhr usage will be screwed. If the solar panels are printed towars the east which is when PG&E pays the least they will not have produced enough energy credits dollars to cover the cost of the electricty they will have to buy back later in the day when the prices ar 3.75 times higher.

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 19, 2018, 06:59:14 am
content: Quote from: fourtytwo42 on April 18, 2018, 07:26:32 pmThe panels themselves aren't even that expensive nowadays. Hence why DIY easily ends up cheaper even if that means giving up any subsidies. Also far more educational and fun! I will always remember the experience of putting together my first solar power system, from designing the system, assembling the electronics, sharing with friends what I did with it, and as an Eta Kappa Nu member, living up to the IEEE slogan "advancing technology for humanity".

author: f4eru
author_rank: Super Contributor
timestamp: April 19, 2018, 10:08:24 am
content: Quote from: DougSpindler on April 19, 2018, 06:23:51 amThat's quite fair, as you receive a rate close or equal to the retail electricity rate.When battery systems become commonplace in a few years, the prices will even out somewhat over the course of a day, the variation will be at a higher scale, bad weather weeks etc...Quote from: DougSpindler on April 19, 2018, 06:23:51 amThat's abuse

author: DougSpindler
author_rank: Super Contributor
timestamp: April 19, 2018, 12:15:27 pm
content: Quote from: NiHaoMike on April 19, 2018, 06:59:14 amYes the pannels might be cheap but if you buy, and install 20 or 30 panels (which the solar companies tell me is what I need to provide 100% of my electricity when maybe I really only need 10 would do the same thing why should I pay two to three times what I really need to pay?

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 19, 2018, 02:28:29 pm
content: Nice part of DIY is that you can start very small and expand as you see fit.If homeowners ending up with a surplus of electricity they can't sell becomes commonplace, I would expect a great increase in the popularity of solar powered crypto mining. And marijuana growing, in areas where it's legal.

author: mtdoc
author_rank: Super Contributor
timestamp: April 19, 2018, 03:30:53 pm
content: A few points:1) It is unlikely that 10 300 +/- watt panels would provide for 100% of your electricity on anything but sunny days. I know the SF Bay area gets lots of sun (I lived their for 7 years) but it is not sunny every day. On a yearly basis 3000 watts nominal of installed PV will be unlikely to cover all the electricity use of a typical small household (especially if any heating or cooling is done with electricity). If you live alone and are frugal with your power usage - then yes, it could.2) Solar installation companies mark up panels quite a bit to pad their profits - so they have an incentive to "upsell" - which should not be surprising.3) DIY does allow you to customize and upgrade your system in stages. I'm in the planning process for doing my 3rd expansion of my system4) What is wrong with producing excess power? Panels are very cheap and IME it's better to "over panel" than under panel. The BOS component cost will generally not go up much at all with increased installed wattage.

author: mmagin
author_rank: Frequent Contributor
timestamp: April 19, 2018, 06:43:21 pm
content: I recall that something went into the NEC recently which no longer allows non-licensed electricians to do PV installs. That would make it one of the only residential things you can't do according to NEC -- most of the other things are industrial. Dunno if that filtered down to the California electric code yet...I also live in the SF bay area. We had neither the time nor inclination to do the install ourselves (I've done some electrical work, but I don't like heights.) So we had 22 panels installed a couple years ago. This is on a south facing roof with 2/12 pitch, flat. I'm not sure if the cost of more sophisticated mounting would be particularly worth the cost. Part of what motivated us to get it done 2 years ago was that the old time-of-use plan was closing (and even for us is being slowly phased out).This produced about 10.76 MW-hour last year - about 1.3MW-hr in the sunniest months, 0.46 MW-hr in the least sunny months.I forget the spec on the panels, we're using a solaredge inverter and 'optimizers'. I shied away from the enphase microinverters due to seemingly more complaints about RFI from the ham radio folks, though the amount of information available was sparse. (And to be honest, I haven't done a lot to see how bad our install is since.) Also I liked how the Solaredge optimizers -- this separates out the MPPT tracking from the central inverter -- were using solid capacitors, which I figured might survive that environment better.

author: metrologist
author_rank: Super Contributor
timestamp: April 19, 2018, 06:50:21 pm
content: The power company will only pay about $0.03 for excess power, and I believe there is a cap on what they credit you. This is determined at the end of year. Also, what they allow you to connect depends on your specific branch, because they have to allow everyone to connect and ensure they can handle the production.Quote from: mtdoc on April 19, 2018, 03:30:53 pmI would expect 3kW of panels to produce ~5 MWHr in a year. That will not nearly cover this use case due to TOU, TOP, and PG&E's rate plans. I suspect that if TOU aligned with TOP, then you would/should be very close.

author: mtdoc
author_rank: Super Contributor
timestamp: April 19, 2018, 08:46:16 pm
content: Quote from: mmagin on April 19, 2018, 06:43:21 pmI don't believe the NEC is in the business of determining who can do an electrical installation. That is up to the local AHJ. As far as I know, there is no restrictions on what type of residential electrical installation can be done by a homeowner in Washington state where I live.BTW, for anyone wanting to do their own solar installation, there are a few active online forums which have many with years of experience, including some professional installers, willing to help with detailed advice.TheNAWS forumis not as good as it used to be but is still one of the best.For those using Midnite Solar equipment theMidnite Solar forumis very good.There are others including some UK specific ones - but I haven't visited them in a while and can't recall their names right now...

author: DougSpindler
author_rank: Super Contributor
timestamp: April 21, 2018, 02:54:08 am
content: Quote from: NiHaoMike on April 19, 2018, 02:28:29 pmSolar coasts a lot of money to set up. Crypto miners are smart. They are mining is a city in New York where the electricity is very inexpensive. Solar would cost them much more.As for pot growers they are making too much money to install mess around with solar. Many just by-pass the electric meter. Far less expensive than solar.

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 21, 2018, 04:36:20 am
content: Dorms and apartments with electricity included in rent used to be prime spots to mine some Bitcoins. That is, until Bitcoin miners became too noisy to be used in that sort of environment. Now college students mine GPU coins, but the main factor is because GPUs have other uses, especially for gamers and those studying a major that can make good use of a good GPU.I used to think that solar and crypto don't go well together because crypto is short term while solar is long term, but then I did combine the two and impressed a lot of my friends...

author: ez24
author_rank: Super Contributor
timestamp: April 21, 2018, 05:15:33 am
content: FYIhttps://lagunita.stanford.edu/courses/Engineering/Solar/Fall2013/about

author: DougSpindler
author_rank: Super Contributor
timestamp: April 26, 2018, 04:22:34 pm
content: Quote from: ez24 on April 21, 2018, 05:15:33 amClass ended on Dec 24, 2013. - This is an archived course.While I'm sure all of the principals have remained the same, is there anything new?

author: ez24
author_rank: Super Contributor
timestamp: April 26, 2018, 06:18:49 pm
content: Quote from: DougSpindler on April 26, 2018, 04:22:34 pmTake a look at Udemy:https://www.udemy.com/courses/search/?q=solar&src=ukw

author: DougSpindler
author_rank: Super Contributor
timestamp: April 26, 2018, 06:54:14 pm
content: Quote from: ez24 on April 26, 2018, 06:18:49 pmThanks I will check it out.

author: TerraHertz
author_rank: Super Contributor
timestamp: May 03, 2018, 02:12:58 pm
content: This thread is a good illustration of why some people (me included) want to simply stop having anything to do with the State-ruined grid. Life's too short to waste time on such a ridiculous maze of requirements and rates. Not to mention the grids becoming ever more unreliable as intermittent 'green' energy sources replace dependable and cheap massive spinning turbines.It's not just homeowners wanting to get off the 'green grid' bullshit train. Here's an industry buying their own coal-fired plant:http://joannenova.com.au/2018/05/gamechanger-chinese-crypto-miners-can-get-8c-cheap-electricity-in-australia-using-old-coal/Btw OP, are you consuming single phase or three phase power?

author: metrologist
author_rank: Super Contributor
timestamp: May 03, 2018, 03:15:38 pm
content: it's not any worse than taxes...

author: DougSpindler
author_rank: Super Contributor
timestamp: May 03, 2018, 07:32:22 pm
content: Quote from: TerraHertz on May 03, 2018, 02:12:58 pmSingle phase.I attended a workshop given by our local power compnay, PG&E about going solar. It was an excellent presentation and they even had Cisco there to talk about Smartmeters and Smart Grid. They did a fantastic job in explaining the history of the power companies and the creation of the grid.Once one understands the history of power compnaies, the creation of the grid and how the grid works, it's no wonder were are in the mess we are now. Cisco estimates it will take well over 100 years to implement a Smartgrid. Why, no one want's to pay for it.I'm all for solar..... But the residential solar industry is filled with thousands of people trying to make a quick fast buck. They don't understand solar and are excellent liars.I still plan to install solar on my home. With the power compnay paying me $0.45 for every kWhr I sell to them I would be a fool not to.

author: metrologist
author_rank: Super Contributor
timestamp: May 03, 2018, 08:36:19 pm
content: Quote from: DougSpindler on May 03, 2018, 07:32:22 pmI don't even pay PG&E half that much for my electric.

author: DougSpindler
author_rank: Super Contributor
timestamp: May 03, 2018, 10:06:23 pm
content: Quote from: metrologist on May 03, 2018, 08:36:19 pmPG&E has 9 different residential rate plans. Which one are you on? If you are on the E1 rate plan, (stright-tiered) PG&E is ending it end of this year. You will be forced to select a different rate plan.We were on the E1/stright-tiered rate plan and ran PG&E's rate plan optimizer tool if we were on another rate plan we could be paying less. In switcing to stright Time of Use our bill dropped $65-75 per month with the same electricity useage.If you haven't compared rate plans, who know you too might be able to save $50 or more?

author: TerraHertz
author_rank: Super Contributor
timestamp: May 04, 2018, 06:35:10 am
content: Quote from: DougSpindler on May 03, 2018, 07:32:22 pmWell, that makes things simpler for you. I gather you've no workshop to worry about powering. I do, which complicates things somewhat. One reason I was so glad to get that big 3-phase UPS recently.http://everist.org/NobLog/20180410_go_fetch.htmQuoteWhy do I have a faint suspicion they may have left out a few awkward details and dissenting opinions?One good source for an alternative view ishttp://joannenova.com.au/Of the Australian grid's problems, but issues are similar worldwide. Her commentary on the South Australian power grid debacle was particularly informative.QuoteOr perhaps it also has something to do with folks understanding that once electricity authorities (and by extension, government) has detailed information on exactly what people are using power for, in real time, the next step will inevitably be forcing people to consume power as theyoughtto be (ie how the gov tells them to.) Do I need to explain how centrally planned anything, always ends up in disaster and ruin?QuoteYep. The general rule applies - do it yourself or don't do it at all. Every time I forget this, I'm painfully retaught it.QuoteAssuming that rebate continues to exist. It's unlikely to for long. But go ahead anyway if you can. It's not about the money, it will become about actually having reliable electric power at all. You'll come to realize that eventually, if things don't change course.

author: mtdoc
author_rank: Super Contributor
timestamp: May 04, 2018, 06:53:10 am
content: Quote from: TerraHertz on May 04, 2018, 06:35:10 amIn addition to state and local utility rebates/incentives, there is a 30% federal tax credit in the US for all purchases related to home solar installations - for now..QuoteYep, that’s primarily why I did it.

author: DougSpindler
author_rank: Super Contributor
timestamp: May 04, 2018, 06:12:11 pm
content: The power company and Cisco I thought gave an excellent presentation on solar and the history of power companies in the US whihc lead to the developvment of the grid.https://www.pge.com/includes/docs/pdfs/shared/solar/solareducation/pv_basics.pdfNot sure why you think solar power is reliable? We all know it's not and neither is wind.I have to say the most reliable souce of electricty for us in California has been PG&E. Can't remember that last time we were without power from PG&E.

author: metrologist
author_rank: Super Contributor
timestamp: May 04, 2018, 06:32:26 pm
content: Quote from: DougSpindler on May 04, 2018, 06:12:11 pmOh, you mean like the other, unreliable power company you could be using...I think solar is fairly reliable, at least within weather norms. It's not predictable day-to-day, but average solar energy should be fairly consistent and we should be able to generate reliable trends... That's does not seem much different than my PG&E experience (YMMV).

author: DougSpindler
author_rank: Super Contributor
timestamp: May 04, 2018, 06:44:04 pm
content: Quote from: metrologist on May 04, 2018, 06:32:26 pm