# Presentation: 477026

## Avoided Emissionsfrom Renewables:Timing is EverythingNREL Energy Analysis Seminar Series

***Avoided Emissions******from Renewables:***_***Timing is Everything***_*NREL Energy Analysis Seminar Series*

_***LFEE***__*: MIT Laboratory for*__*	*__*Energy and the Environment*_

***Stephen Connors******Mike Berlinski, Kate Martin, Mike Adams***
*Analysis Group for Regional Electricity Alternatives****Laboratory for Energy and the Environment*** ***Massachusetts Institute of Technology***
- One Amherst St., Cambridge, MA 02139-4307, USA

## Timing Isn’t Everything...

*But will be for *_this_* talk*
*Avoided Emissions from Renewables is Really**	**a Story About **Multiple** “**Resource Dynamics**”*
- Solar and Wind	• Hydro and Biomass
- Electricity Demand	• Fossil (and other) Dispatch
- Energy Market Dynamics (both electric and fuel)
*Which Fossil Generation Displaced?*
- Load Shape Following (LSF) Fossil
- Powerpool-Specific Hourly “LSF Avoided Emission Rates”
*Avoided Emissions from **Solar PV* (EPA)
*Offshore Wind** in the Northeast* (MA-RET/GE/DOE)
*Implications for **Future Research** (All in an hour!)*
- Statistics vs. Operational “Modes” and “Thresholds”
- Technology Cost, Performance and Complexity

## Fossil Unit Dispatch/Duty Cycle	and “Avoided Emissions”

- “Real-life Data”* (Historical, Hourly)*
- Fossil Unit Operations (EPA Clean Air Markets)
- Regional Power Pool Loads & Prices (NERC Subregions)
- Actual or Simulated Renewable Generation	(using hourly weather data - insolation/windspeed)

- Some interesting (e.g. challenging)	dynamics and implications
- Renewable power is “state specific”
- Short-time duration: solar, wind, others
- Medium & long time scales: hydro and biomass
- Fossil dispatch is *also* very state specific
- Available generation (maintenance, hydro & nuclear availability)
- Level of Demand (capacity margin)
- Factors affecting dispatch order (fuel costs, reserve markets)
- How do they interact?

## Fossil Unit Operation Modes

- Generation is generally thought of as “**baseload**,”	“**intermediate**,” “**peaking**,” and/or “**spinning**.”
- In reality, unit “**dispatch**” is much more complex
- However, several “**Operation Modes**” have been	observed by looking at hourly operations.

- Even these modes do not, in an of themselves,	tell us which units respond to increases in	renewable generation, or changes in demand
- These units we call ***Load Shape Following***

## How Do They Really Run?

- Fourteen Days in January 2002

## How Do They Really Run?

_*How Do They Really Run?*_

- Fourteen Days in July 2002

## How Do Renewables Run?

_*How Do Renewables Run?*_

- Fourteen Days in January & July

## Example: Peak Demand

_*Example: Peak Demand*_

*Representative**Northeast**Generators*

## Example: Overnight/Off-Peak

_*Example: Overnight/Off-Peak*_

*Representative**Northeast**Generators*

## A Year “At a Glance”

*365*
*Days *
*of*
*Year*

*24 Hours of Day*

**Total Load Profiles**
- are normalized to
- peak subregion
- demand in 2002

**eGrid Fossil **
**Generation Profiles**
- are normalized to
- peak subregion
- eGrid generation
- in 2002.

- Fraction of
- 2002 Peak

_*A Year “At a Glance”*_

## LSF Avoided Emissions Rates

**Load Shape Following**
**Emission Rate Profiles**
- represent emissions from
- 1MWh of load shape following
- generation in each hour. These
- are the emissions offset by
- 1MWh of non-emitting generation
- applied in each hour of the year.
- Units are kg/MWh in each hour.

- SO2 Offset
- (kg/MWh)

_*LSF Avoided Emissions Rates*_

## Generation from Photovoltaics

**PV Generation Profiles**
- Show hourly PV generation as a
- fraction of monitored capacity.
- Units are kWh/kWcap in each
- hour.

- kWh/kWcap

_*Generation from Photovoltaics*_

## Avoided Emissions from PVs

**Emissions Offset from PV:**
- Offsets are the product of
- hourly PV generation
- as a fraction of monitored capacity
- and the hourly load shape
- following emission rates in the
- subregion.
- Units are g/kWcap in each hour.

- g/kWcap

_*Avoided Emissions from PVs*_

## Some Select Subregions

_*Some Select Subregions*_

***	******The East***
- New England (NEWE)
- Ohio Valley (ECOV)
- Texas (ERCT)

- 	***The West***
- Pacific Northwest (NWPN)
- Southwest (WSSW)
- California (CALI)

## The East: Operating Hours

_*The East: Operating Hours*_

- (eGrid Only)

## New England–by the hour

***New England***(NEWE-2002)

- • 365 days x 24 Hours
- • Total Load/Elec. Demand
- • Fossil Generation    (Normalized to 2002 Peak Load)
- + Fossil emissions rates     (kg/MWh) are for     weighted “Load Shape     Following” generating     for that hour.

## Ohio Valley–by the hour

_*Ohio Valley–by the hour*_

- Load

- Fossil Gen

- SO2/MWh

- NOx/MWh

- CO2/MWh

- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec

***Ohio Valley***(ECOV-2002)

- • 365 days x 24 Hours
- • Total Load/Elec. Demand
- • Fossil Generation    (Normalized to 2002 Peak Load)
- + Fossil emissions rates     (kg/MWh) are for     weighted “Load Shape     Following” generating     for that hour.

## Texas–by the hour

_*Texas–by the hour*_

- Load

- Fossil Gen

- SO2/MWh

- NOx/MWh

- CO2/MWh

- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec

***Texas***(ERCT-2002)

- • 365 days x 24 Hours
- • Total Load/Elec. Demand
- • Fossil Generation    (Normalized to 2002 Peak Load)
- + Fossil emissions rates     (kg/MWh) are for     weighted “Load Shape     Following” generating     for that hour.

## New England–PV by the hour

_*New England–PV by the hour*_

***New England***(NEWE-2002)

- • 365 days x 24 Hours
- • Total Load/Elec. Demand
- • PV Generation    (**Monitored** Systems, normalized      to 1 kW of installed PV capacity)
- + Avoided LSF fossil     emissions from PV     generation (kg per hour)

## Ohio Valley–PV by the hour

_*Ohio Valley–PV by the hour*_

- Load

- PV Gen

- SO2 kg

- NOx kg

- CO2 kg

- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec

***Ohio Valley***(ECOV-2002)

- • 365 days x 24 Hours
- • Total Load/Elec. Demand
- • PV Generation    (**Monitored** Systems, normalized      to 1 kW of installed PV capacity)
- + Avoided LSF fossil     emissions from PV     generation (kg per hour)

## Texas–PV by the hour

_*Texas–PV by the hour*_

- Load

- PV Gen

- SO2 kg

- NOx kg

- CO2 kg

- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec

***Texas***(ERCT-2002)

- • 365 days x 24 Hours
- • Total Load/Elec. Demand
- • PV Generation    (**Monitored** Systems, normalized      to 1 kW of installed PV capacity)
- + Avoided LSF fossil     emissions from PV     generation (kg per hour)

## The West: Hours and Energy

_*The West: Hours and Energy*_

- (eGrid Only)

## Pacific NW–by the hour

_*Pacific NW–by the hour*_

- Load

- Fossil Gen

- SO2/MWh

- NOx/MWh

- CO2/MWh

- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec

***Pacific NW***(NWPN-2002)

- • 365 days x 24 Hours
- • Total Load/Elec. Demand
- • Fossil Generation    (Normalized to 2002 Peak Load)
- + Fossil emissions rates     (kg/MWh) are for     weighted “Load Shape     Following” generating     for that hour.

## Southwest–by the hour

_*Southwest–by the hour*_

- Load

- Fossil Gen

- SO2/MWh

- NOx/MWh

- CO2/MWh

- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec

***Southwest****** ***(WSSW-2002)

- • 365 days x 24 Hours
- • Total Load/Elec. Demand
- • Fossil Generation    (Normalized to 2002 Peak Load)
- + Fossil emissions rates     (kg/MWh) are for     weighted “Load Shape     Following” generating     for that hour.

## California–by the hour

_*California–by the hour*_

- Load

- Fossil Gen

- SO2/MWh

- NOx/MWh

- CO2/MWh

- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec

***California***(CALI-2002)

- • 365 days x 24 Hours
- • Total Load/Elec. Demand
- • Fossil Generation    (Normalized to 2002 Peak Load)
- + Fossil emissions rates     (kg/MWh) are for     weighted “Load Shape     Following” generating     for that hour.

## Across NERC Subregions...

- PV Generation & Avoided Emissions

- LSF = Load Shape Following // SOF = Slice of Fossil (eGrid)

## Mid-Atlantic – Best Time?

_*Mid-Atlantic – Best Time?*_

- Load

- Fossil Gen

- LSF SO2

- LSF NOx

- LSF CO2

- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec

***Mid-Atlantic (PJM)****** ***(MAAC-2002)

- • 365 days x 24 Hours
- • Total Load/Elec. Demand
- • Fossil Generation    (Normalized to 2002 Peak Load)
- + Fossil emissions rates     (kg/MWh) are for     weighted “Load Shape     Following” generating     for that hour.

## Implications/Opportunities

- What about other Renewables?
-  Windpower (Onshore/Offshore)
-  Hydropower (Integrated/Deferred)
-  Sustainable Biomass
- What about Energy Conservation?
-  Can We “Target” DSM for Emissions		Reductions?
-  Should Certain Appliances Be Pushed?		(Heat Pumps over Air Conditioners?)
- What Role Distributed Generation?
- What Role T&D & Energy Storage?

## Dynamics in Space and Time

*Source: Mass Renewable Energy Trust** TrueWind Solutions*

## Where & When Is It Windy?

_*Where & *__*When*__* Is It Windy?*_

-  Look “Near Shore”	(Data from two NOAA Buoys)
-  Near Hull Wind Turbine
- “Near” Cape Wind Site
-  How Much?
-  How Predictable?

*(Source: GE Wind)*

*Slightly Higher Winds Yield Much Higher kWh Production!*

## Multi (2)-Year Performance

*Highly Variable in Production, Revenues**	**and Avoided Emissions*

## Demand, Price & Revenues ‘01

_*Demand, Price & Revenues ‘01*_

*Source Data: ISO-NE, NOAA*

- Mass Bay ’01

- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec

- Buzz Bay ’01

- (MWh)

- (MWh)

## Demand, Price & Revenues ‘02

- Load 2002

- MCP 2002

- (GW)

- ($/MWh)

_*Demand, Price & Revenues ‘02*_

*Source Data: ISO-NE, NOAA*

- Mass Bay 02

- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec

- Buzz Bay 02

- (MWh)

- (MWh)

- Mass Bay02

- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec

- Buzz Bay 02

- ($)

- ($)

## Looking Longer & Further Out...

- 20 NOAA stations selected for analysis; starting with 6 select							 “data sites” (3 Near, 3 Far)

| Station | Distance (nm) | Depth (m) | Height (m) |
| --- | --- | --- | --- |
| Portland | 10 | 20 | 5 |
| Gulf of Maine | 80 | 20 | 5 |
| Boston | 20 | 50 | 5 |
| Buzzard’s Bay | 30 | 25 | 25 |
| Nantucket | 50 | 60 | 5 |
| Hotel | 200 | 3,000+ | 5 |

- (Calm seas)

- Hub Height @ 75m

## Wind Energy by Hour & Month

_*Wind Energy by Hour & Month*_

*Buzzard’s Bay**	**	**	**	*_*Nantucket*_

*Boston**	**	**	**	**	*_*Hotel*_

***Total**** Generation **by month and**hour of day.*

- _Far offshore_

- _Near shore_

*Source Data: NOAA*
*( Wind Speeds Scaled to 75m )*

_*For One MW of Installed Wind Capacity*_*(At 75m using GE Wind 3.6 MW Power Curve)*

## Average Annual Windspeed @ 75m

- Average windspeeds vary considerably from year to year.

*Source Data: NOAA*

_*Preliminary results – Please do not cite without permission*_*   *MIT/UMass-Amherst Pilot Project **Offshore Wind Collaborative****   ***Sponsors*: Mass. Renewable Energy Trust/GE-Wind/U.S. DOE

## Annual Capacity Factors

- Differences in wind resources across data sites are magnified	when we go from windspeeds to energy production.

_*Preliminary results – Please do not cite without permission*_*   *MIT/UMass-Amherst Pilot Project **Offshore Wind Collaborative****   ***Sponsors*: Mass. Renewable Energy Trust/GE-Wind/U.S. DOE

*Source Data: NOAA, GE*

*Power production at a 75m hub height using a **GE Wind 3.6 MW Power Curve (104m dia.)*

## Average Windspeeds @ 75m

*Source Data: NOAA*

_*Preliminary results – Please do not cite without permission*_*   *MIT/UMass-Amherst Pilot Project **Offshore Wind Collaborative****   ***Sponsors*: Mass. Renewable Energy Trust/GE-Wind/U.S. DOE

## Average Windspeeds @ 75m

_*Average Windspeeds @ 75m*_

*Source Data: NOAA*

*The three far** offshore data*
* **sites and** Buzzard’s Bay**

- * The Buzzard’s Bay data site is closer to shore than Nantucket, though it	is windier than Nantucket for many (but not all)  of the last 15 years	 - though this may be due to height scaling issue.

_*Preliminary results – Please do not cite without permission*_*   *MIT/UMass-Amherst Pilot Project **Offshore Wind Collaborative****   ***Sponsors*: Mass. Renewable Energy Trust/GE-Wind/U.S. DOE

*• **A Closer Look...*

## Average Capacity Factors

*Source Data: NOAA, GE*

*Power production at a 75m hub height using a **GE Wind 3.6 MW Power Curve (104m dia.)*

_*Preliminary results – Please do not cite without permission*_*   *MIT/UMass-Amherst Pilot Project **Offshore Wind Collaborative****   ***Sponsors*: Mass. Renewable Energy Trust/GE-Wind/U.S. DOE

*The three far** offshore data*
* **sites and** Buzzard’s Bay**

## Volatile Capacity Factors

_*Volatile Capacity Factors*_

*Source Data: NOAA, GE*

*Power production at a 75m hub height using a **GE Wind 3.6 MW Power Curve (104m dia.)*

_*Preliminary results – Please do not cite without permission*_*   *MIT/UMass-Amherst Pilot Project **Offshore Wind Collaborative****   ***Sponsors*: Mass. Renewable Energy Trust/GE-Wind/U.S. DOE

*• **Percent Change from Previous Year’s Capacity Factor*

## Variability Matters!

- (Renewable) Resource Variability
- Wind and Sun (Magnitude and Timing)
- Rainfall (Hydropower, Biomass)
- Fuel Markets
- Fuel Prices/Price Differentials  (esp. Natural Gas)
- Infrastructure Investments (Pipelines/Storage/LNG)
- Conventional Generation
- Nuclear Availability, Hydro Potential
- Power Market Structure (Capacity Markets, Bid Rules)
- Power Grid Operations (Reliability/Contingency Practices)
- Energy Demands
- Demand Growth – Relative to Supply Growth
- Heating Degree Days/Cooling Degree Days

## Scenario “Resolution” & Models

- Scenario Modeling – Lots of “Flavors”
- Bottom-Up, Top-Down
- Optimization vs. Simulation
- System-Dynamics, Agent-Based
- The Finer the Resolution, the More	Prescriptive Results Will Be
- Computers are only getting more powerful

## Using History in Modeling..

-  Multiple/Coupled	Renewable Resources

- How to Best Use High Resolution Data in	Future Scenarios/Pathways Analysis?

## Using History in Modeling..

-  Multiple/Coupled	Renewable Resources

- How to Best Use High Resolution Data in	Future Scenarios/Pathways Analysis

## Using History in Modeling..

-  Multiple/Coupled	Renewable Resources

- How to Best Use High Resolution Data in	Future Scenarios/Pathways Analysis

## Using History in Modeling..

-  Multiple/Coupled	Renewable Resources

- How to Best Use High Resolution Data in	Future Scenarios/Pathways Analysis

## Using History in Modeling..

-  Multiple/Coupled	Renewable Resources

- How to Best Use High Resolution Data in	Future Scenarios/Pathways Analysis

## Using History in Modeling..

-  Multiple/Coupled	Renewable Resources

-  Supply, Demand and	Markets Prices

- How to Best Use High Resolution Data in	Future Scenarios/Pathways Analysis

## Using History in Modeling..

-  Multiple/Coupled	Renewable Resources

-  Supply, Demand and	Markets Prices

- How to Best Use High Resolution Data in	Future Scenarios/Pathways Analysis

## Using History in Modeling..

-  Multiple/Coupled	Renewable Resources

-  Generation and Fuel	Market Dynamics

- How to Best Use High Resolution Data in	Future Scenarios/Pathways Analysis

## Operating Modes and	“Resource” Portfolios

- Renewable Resource Variability
- Wind and Sun (Magnitude and Timing)
- Rainfall (Hydropower, Biomass)
- Fuel Markets
- Fuel Prices/Price Differentials  (esp. Natural Gas)
- Infrastructure Investments (Pipelines/Storage/LNG)
- Conventional Generation
- Nuclear Availability, Hydro Potential
- Power Market Structure (Capacity Markets, Bid Rules)
- Power Grid Operations (Reliability/Contingency Practices)
- Energy Demands
- Demand Growth – Relative to Supply Growth
- Heating Degree Days/Cooling Degree Days

## (More) Outstanding Questions...

- Daily, Seasonal, and Inter-Annual	Dynamics Matter!
- Are there Climate Change implications?
- On/Off Generation Better than	Up/Down Generation?
- Are a “bank of diesels” better than one largefossil steam unit running many hours in standby?
- Environmental Benefits from	Power Grid “Modernization?”
- Reducing transmission bottlenecks may have  (operational) environmental benefits.
- How Beneficial Might Storage Be?
- Can you come out ahead by reducing the number	of hours in “Standby” generation mode?
- Too Much of a “Good” Thing?
- What about “greater than marginal” Renewable kWhs?
- What if more fossil gets pushed into “Standby” mode?

## Have We Had It Too Easy?

_*Have We Had It Too Easy?*_

- We need to develop *tools* and *information*	for a more distributed, less dispatchable	energy sector.