Sand-Based High Temperature Seasonal Heat Storage byPolar Night Energy Oy
Avoided Emissions Framework – Level 2 version 0.8 assessment≈100 MtCO₂e/year in 2030
Assessment conducted: 2020Contents
OVERVIEW .......................................................................................................................................................... 2
METHOD ............................................................................................................................................................. 3
ASSESSMENT ...................................................................................................................................................... 5
DESCRIPTION OF THE INNOVATION ........................................................................................................................... 5
READINESS LEVELS ............................................................................................................................................... 5
MECHANISM FOR AVOIDING CARBON EMISSIONS......................................................................................................... 5
CALCULATION ..................................................................................................................................................... 5
SENSITIVITY ANALYSIS ........................................................................................................................................... 7
RESULTS AND DISCUSSION...................................................................................................................................... 8
UNITED NATION SUSTAINABLE DEVELOPMENT GOALS (SDG) ........................................................................................ 9INVENTORY OF KEY DATA SOURCES ........................................................................................................................... 9REFERENCES ..................................................................................................................................................... 10

Supported by:rev 200910

Overview
In Mission Innovation’s Net-Zero Compatible Innovations Initiative, assessments are being performed
following the Avoided Emissions Framework (AEF) guidance [1].The aim of the assessments is toestimate the potential avoided greenhouse gas (GHG) emissions per year in 20301 enabled by SandBased High Temperature Seasonal Heat Storage and other similar competing innovations.
Any assessment of this nature requires significant assumptions, and the result has a high degree ofuncertainty. Thus, this report describes the calculation method, data sources and assumptions usedfor this avoided emission assessment.
The Sand-Based High Temperature Seasonal Heat Storage enables storage of renewable energy whenthe energy production conditions are beneficial. The stored renewable energy can then be used indifferent energy demanding processes, replacing fossil-based combustion technologies that arecommon nowadays for heating and electricity production. This innovation is provided by Polar Night
Energy Oy (PNE), a company with headquarter in Tampere, Finland.
With the heat storage, surplus energy from solar and wind power can be stored during periods ofhigh production. The stored heat can then be used to replace energy input from fossil fuels forinternal heat and electricity generation. Compared to combustion-based technologies, combining
solar and wind power with the PNE storage allows the reduction of CO2 emissions from energy use by
772.8 gCO₂e/kWh.
Sand-Based High Temperature Seasonal Heat Storage enables the potential avoidance of
169.8 MtCO₂e/year in 2030.
A simplified sensitivity analysis gives potential lower and upper values of 56.6 MtCO₂e/year and283.1 MtCO₂e/year, respectively.

1Avoided emissions are calculated for the year 2030 as MtCO2 equivalent per year. The estimation is NOT
cumulative.
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MethodThis assessment estimates the annual avoided emissions potential of the innovation and potential
competing innovations for the year 2030, as part of Mission Innovation’s Net-Zero Compatible
Innovations Initiative aiming at identifying innovations that can significantly contribute todecarbonisation by 2030.
The assessment method follows the guidance provided in the Avoided Emissions Framework (AEF)[1]. To demonstrate the benefit of the innovation to reduce overall system level GHG emissions, thisassessment quantifies and compares the GHG emissions from a business-as-usual (BAU) baseline
scenario with those from an innovation-enabled scenario. This involves calculating emissions in thefollowing categories:•BAU scenario. The emissions from the BAU baseline, without the introduction of theenabling innovation.

•Innovation scenario. The emissions from the innovation-enabled scenario: a scenario wherethe enabling innovation is introduced.

•Potential enabled avoided emissions: The potential avoided emissions due to the activities
avoided as a result of using the innovation.
𝐸𝑛𝑎𝑏𝑙𝑒𝑑 𝑎𝑣𝑜𝑖𝑑𝑒𝑑 𝑒𝑚𝑖𝑠𝑠𝑖𝑜𝑛𝑠 = 𝐼𝑛𝑛𝑜𝑣𝑎𝑡𝑖𝑜𝑛 𝑠𝑐𝑒𝑛𝑎𝑟𝑖𝑜 − 𝐵𝐴𝑈 𝑠𝑐𝑒𝑛𝑎𝑟𝑖𝑜•

Innovation emissions: The life cycle emissions (i.e. direct and indirect emissions) of theinnovation.

•Rebound effects: The increase in BAU emissions occurring as result of the enabling
innovation implementation.

Further information required to quantify absolute potential avoided emissions, includes:•Market Volume. Volume of potential deployment of the innovation in a specific geography
by 2030.2•Market Share. Proportion of the market volume that could be dominated by the innovation
under assessment by 2030.3

2

An important issue of future-oriented avoided emission assessments is the calculation of the future market for an innovation. There is noexpert consensus yet on a systematic way to approach this issue. Thus, the future market volume is calculated ad-hoc and based on
information from the innovation provider.
3The market share is normally based on an extrapolation of existing market developments or on the market that the innovation isexpected to develop.

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Using the information below we can derive:•Net potential avoided emissions= 𝑃𝑜𝑡𝑒𝑛𝑡𝑖𝑎𝑙 𝑒𝑛𝑎𝑏𝑙𝑒𝑑 𝑎𝑣𝑜𝑖𝑑𝑒𝑑 𝑒𝑚𝑖𝑠𝑠𝑖𝑜𝑛𝑠 − 𝐷𝑖𝑟𝑒𝑐𝑡 𝑖𝑛𝑛𝑜𝑣𝑎𝑡𝑖𝑜𝑛 𝑒𝑚𝑖𝑠𝑠𝑖𝑜𝑛𝑠 − 𝑅𝑒𝑏𝑜𝑢𝑛𝑑 𝑒𝑚𝑖𝑠𝑠𝑖𝑜𝑛s•

Carbon Abatement Factor4 = Net potential avoided emissions per unit quantity of theinnovation implemented.

This assessment evaluates future potential avoided emissions. Thus, there is uncertainty about thefuture development and deployment of this innovation that needs to be considered. The AvoidedEmissions Framework (AEF) provides guidance on how to assess future potential scenarios. It
suggests considering two factors: the probability of success of the innovation, and the probability ofadoption of the innovation. In this assessment we have included the two probability factors together
within a ‘market share’ factor.
The calculation can then be summarised as follows:

Net Potential Avoided Emissions= Carbon Abatement Factor × Market Volume × Market share

4A carbon abatement factor is a normalised factor reflecting the avoided emissions per unit of innovation implemented. This factor
provides consistency and comparability among studies. It can be thought as an analogous to “emission factors” used in product footprints.

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Assessment
Description of the innovation
The Sand-Based High Temperature Seasonal Heat Storage enables storage of renewable energy when
the production conditions are beneficial. The stored renewable energy can be used in different
energy demanding processes, replacing fossil-based combustion technologies that are commonnowadays [2].

Readiness levels
The Technology Readiness Level (TRL) of this innovation is 7: System prototype demonstration inoperational environment. Pilot plant operational and connected to local heating grid [2].
The Business Readiness Level (BRL) of this innovation is: 6: Full business model including pricing
verified on customers. First offers have been sent and all components are verified in terms of prices
and applicability [2].
The TRL and BRL were assessed using the innovators information and following the EU Horizon 2020
guidelines [3] and KTH Innovation Readiness level™ model [4].

Mechanism for avoiding carbon emissions
The Sand-Based High Temperature Seasonal Heat Storage avoids emissions through one main
mechanism. The solution enables upscaling and more effective use of wind and solar energy asenergy can be stored during periods of high supply and used during periods of high demand. As thesolution enables heat storage up to 700°C it allows the replacement of fossil fuels used for bothheating and steam production, as well as electricity generation [2].

Calculation
Market Volume
The market is defined in terms of renewable energy made available thanks to storage possibilities.
Since the world energy use is to be transformed to 100% renewable energy, the energy storage
capacity needs to be considerably developed. In this assessment it was assumed that 17% of thegenerated renewable energy will need to be stored by technologies similar to that offered by PolarNight Energy Oy [5]. With a projected gross electricity production of 4 390 TWh from solar and wind
power in 2030 [6], the storage technologies will enable the replacement of 737 TWh of fossil-basedenergy. Hence, the total potential market is 737 TWh.
Market share
The innovation is the most effective for industrial usage where high temperatures are needed. It is,however, difficult to forecast this kind of energy demand in 2030. The market share is an assumption
made by the assessor and is set to 30% of the available renewable energy that needs to be stored.

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The relatively high market share is chosen due to the solutions variety in use. As the solution can beused to generate both electricity and heat, for industrial use and in district heating system – thesupply of excessive renewable energy will be a more significant limiting factor for the innovations
carbon abatement potential than the ability to take market shares.
Net Potential Avoided Emissions
1. BAU scenario
According to IEA projections, the industry sector in 2030 will have a demand of 38 505 TWh of fossilbased energy from coal (42%), oil (28%) and natural gas (30%) [6]. The fossil-based energy has anaverage emission factor of 795.9 gCO2e/kWh (Coal 1 001 gCO2e/kWh; oil 840 gCO2e/kWh; naturalgas 469 gCO2e/kWh) [7].
2. Innovation scenario
Considering a technical lifetime of 30 years, the innovation has an emission factor of
2 gCO2e/kWh related to production and deployment of the heat storage [2].
Energy supply forecasts from IEA suggest that the ratio between solar and wind energy
will be approximately 1/3 solar energy and 2/3 wind energy in 2030 [6]. Using emission
factors for wind power as 12 gCO2e/kWh, solar photovoltaics (PV) as 46 gCO2e/kWhand concentrated solar power (CSP) as 22 gCO2e/kWh [8] gives an average emission
factor of 23.12 gCO2e/kWh for stored renewable electricity.
Including both deployment emissions and emissions from renewable electricity
production, the emissions add up (23.12 gCO2e/kWh + 2 gCO2e/kWh) to25.12 gCO2e/kWh.
The storage has a thermal efficiency of 91% [2]. Assuming that the coal, oil and natural
gas input to the industrial sector is primarily used for heat production, this gives a total
impact from the innovation scenario as 25.12 / 91% = 27.61 gCO2e/kWh.
3. Rebound effects5
Potential negative rebound effects are e.g. increased energy usage when heat and power is clean(psychological effect) [2]. A positive indirect effect is reduced fuel transportation. However, theemissions from fuel transportation will have a minor effect on the total result and have therefore notbeen evaluated.

5Rebound effects may be caused by related consequential effects or by unrelated (and sometimes unintended) effects and are oftencaused by human behavioural changes in demand for carbon-intensive goods or activities.

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4. Net potential avoided emissions
Carbon Abatement Factor
The carbon abatement factor is the difference between the avoided CO2 emissions per kWh whenusing solar and wind power combined with the innovation, and those when using the fossil-basedenergy (oil, coal, natural gas):795.9 gCO2e/kWh (fossil-based energy) – 27.6 gCO2e/kWh (renewable energy + innovation impact) =772.8 gCO2e/kWh.
To increase transparency, the net avoided emissions are again presented using theequation from the Method section.

𝑁𝑒𝑡 𝑎𝑣𝑜𝑖𝑑𝑒𝑑 𝑒𝑚𝑖𝑠𝑠𝑖𝑜𝑛𝑠 = 772.8

𝑔𝐶𝑂2 e𝑘𝑊ℎ× 736.8 TWh × 30 % = 𝟏𝟕𝟎 𝑴𝒕𝑪𝑶𝟐 𝐞

Table 1 outlines the values of the terms in the equation above.
Table 1. Calculation factors and assessment resultUnitValuegCO2e/kWh772.8

Market VolumeTWh736.8

Market share%30MtCO₂e/year

170Carbon Abatement Factor

Net Potential Avoided Emissions

Sensitivity Analysis
In order to give some perspective to the results, a simple sensitivity analysis was performed bychanging assumptions. The increased emissions from the innovation up to 10 gCO2e/kWh is anassumption to show the relative insignificance of the factor on the total result.
According to calculations made by the innovator, forecasts regarding need for energy storage ranges
between 10% and 20% of the renewable energy production. These lower and upper values havebeen tested in the sensitivity analysis in Table 2.

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Table 2. Sensitivity analysis

Scenarios

Change from base caseBase case

Net potential avoided emissions(MtCO₂e/year)
169.8

Reduced market share

Reduced from 30% to 10%

56.6

Increased market share

Increased from 30% to 50%

283.1

Increased emission fromIncreased from 2 to

167.9

innovation

10 gCO2e/kWh

Reduced need of stored

Reduced from 17% to 10%

101.2

Increased from 17% to 20%

202.4

energyIncreased need of stored
energyResults and discussion
The Sand-Based High Temperature Seasonal Heat Storage and other innovations like it are estimatedto enable the potential avoided emissions of 170 MtCO₂e/year in 2030.
A simplified sensitivity analysis gives potential lower and upper values of 57 MtCO₂e/year and283 MtCO₂e/year, respectively.
This assessment can only provide an approximate estimate at best since it is attempting to calculatea figure of potential avoided emissions that the impact of a new technology will have in more than
10 years’ time. It is therefore subject to considerable uncertainty.
The potential avoided emissions are dependent on the future development of renewable energy
installations, as the magnitude of fossil fuel replacement is confined to the surplus renewable energy
production. The other way around, possibilities to store intermittently produced renewable energy
could also facilitate a growth of the renewable electricity sector.
In this assessment, the magnitude of potential carbon saving is limited by the generation ofrenewable energy that needs to be stored. However, it can be argued that the innovation also hasthe potential to enable the transformation from fossil-based combustion technologies to renewableones, even though the energy comes from other sources than excessive solar and wind energy. In
this way the carbon saving potential of the innovation is significantly larger than the assessment
indicates.
One current obstacle on the European market is that EUs energy tax does not take the supply anddemand of energy into consideration. One of the benefits of the innovation is that it can be charged
with energy during periods when there is a large supply of energy at low cost. If the energy tax
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remains the same in periods of low demand, there is a risk that the profitability of the innovation isnegatively affected. Regulations will probably have a large effect on how fast the innovation will beimplemented in industries at a global scale.
The innovation also has the potential to be used in district heating systems. The innovator has done
calculations on the application of the innovation in the district heating system of Helsinki, and theresults indicate the 96% of CO2e saving compared to a BAU scenario. However, this is a complex
system and the efficiency of the system depends on further factors than the implementation of theinnovation, e.g. the expansion of wind energy generation. Therefore, this market has not been
evaluated in this assessment.

United Nation Sustainable Development Goals (SDG)
The innovation has been identified as potentially relevant to the Sustainable Development Goals(SDG) defined by the United Nations [8]. Based on the data acquired by the assessor the innovation
may have the following effects:••

Strong positive impact on SDG nr 7: Affordable and clean energy
Motivation: In alignment with SDG target 7.2: “By 2030, increase substantially the share ofrenewable energy in the global energy mix”. The innovation enables upscaling of wind andsolar energy. In that way clean energy is available during periods where it today is notavailable.
Partial positive impact on SDG nr 9: Industry, Innovation, and Infrastructure
Motivation: In alignment with SDG target 9.2 “Promote inclusive and sustainableindustrialization and, by 2030, significantly raise industry’s share of employment and grossdomestic product, in line with national circumstances, and double its share in least developedcountries”. The innovation enables access to cheap and clean energy during all hours.

Inventory of key data sources
Table 3. Summary of data sources for calculations

Data item description

Referenc

Page number / locationeEnergy storage capacity in 100%

[5]

P. 27

Energy generation[6]“World” tabEnergy consumption[6]“World” tabElectricity Emission Factor projections[8]“Global” tabrenewable system

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References[1]

Stephens, A and Thieme, V. (2019). The Avoided Emissions Framework (AEF). Available athttps://misolutionframework.net/pdf/Net-Zero_Innovation_Module_2The_Avoided_Emissions_Framework_(AEF)-November_2019.pdf[2]

Material from Polar Night Energy[3]

EU Horizon 2020 (2015). Technology readiness levels (TRLs). Work programme 2014-2015
general annexes. Available at:https://ec.europa.eu/research/participants/data/ref/h2020/wp/2014_2015/annexes/h2020wp1415-annex-g-trl_en.pdf[4]

KTH Royal Institute of Technology (2020). KTH Innovation Readiness Level TM. Available at:https://kthinnovationreadinesslevel.com/take-a-tour/[5]

Pleßmanna, G. et al. (2014). Global energy storage demand for a 100% renewable electricity
supply. Published in Energy Procedia, Volume 46, 2014, Pages 22-31. Available at:https://www.sciencedirect.com/science/article/pii/S1876610214001702[6]

International Energy Agency, Energy Technology Perspectives 2017. Available at:www.iea.org/etp2017[7]

IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation (2011),available at: http://www.ipcc-wg3.de/report/IPCC_SRREN_Annex_II.pdf[8]

United Nations Department for Economic and Social Affairs. United Nations Sustainable
Development Goals [Internet]. 2020 [cited 2020 Oct 16]. Available from:https://sdgs.un.org/goals

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