andrew.bissell@sunamp.com@sunampltd

01875 610001

Optimising Electrical Systems via Smart Heat Batteries

Presented at

Energy Storage and Connected Systems 7th February 2018

Takeaways and Problem Statement

Top 3 key learnings or takeaways

1. What is a Heat Battery?

2. What is the benefit of making Heat Batteries smart?

3. Cost benefit analysis of Heat Batteries compared with other energy storage for balancing electric grids

Problem Statement • Electricity grids with renewables are

intermittent at scales from weeks (high pressure system, no wind) to sub-second (frequency regulation)

• Heat demand is intermittent (scale of hours to seasons) and the amplitude is much greater than electricity demand

• Can we be smart and harness these two intermittences via something (say a smart heat battery) to solve both together?

Electricity intermittency

Courtesy of Gridwatch

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Week of 1-7 Feb 2010

Series1

Heat demand intermittency versus electric demand

Courtesy of Dr Robert Sansom (personal communication & thesis) and Richard Lowes (twitter: @heatpolicyrich & blog)

It looks impossible for electricity to meet the Heat demand. But a more granular view shows this is a couple of peaks of demand per day – when heating is on and people are showering. This does not have to be met from instantaneous gas heating. Stored heat smooths it to average.

Sansom, R. (2014), Decarbonising low grade heat for a low carbon future: A thesis submitted

to Imperial College London for the degree of Doctor of Philosophy. London: Imperial College.

http://blogs.exeter.ac.uk/energy/2017/07/10/is-the-peak-heat-issue-all-its-made-out-to-be/

Heat demand intermittency versus electric demand

Courtesy of Dr Robert Samson (personal communication & thesis) and Richard Lowes (twitter: @heatpolicyrich & blog)

Sunamp own re-interpretation of Dr Samson‘s 2010 heat demand data is based on averaging to distributed thermal storage (green curve). Assuming COP 2.75 heat pump is used to charge thermal storage, the extra electricity demand is the blue curve.

The problem looks manageable. i.e. << less than doubling electricity demand, if every building has a heat pump with storage.

More storage should enable the increase to come from moments where the grid has excess renewable electricity to offer.

Sansom, R. (2014), Decarbonising low grade heat for a low carbon future: A thesis submitted

to Imperial College London for the degree of Doctor of Philosophy. London: Imperial College.

http://blogs.exeter.ac.uk/energy/2017/07/10/is-the-peak-heat-issue-all-its-made-out-to-be/

Sunamp Heat Battery Vision

Disrupt the hot water cylinder market with a better, smaller, more efficient heat store that fits beautifully into small, modern living and working places.

Return storage to homes that, because of the trend to combi boilers, are becoming “storage poor”.

Support the transition to intermittent renewable energy especially PV on buildings, wind in the Grid and heat pumps.

How do they store heat?

High Energy Density

Melting and freezing a PCM (Phase Change Material) stores 3-4 times as much energy as heating water

Hand warmer (melts at 58°C)

High Power

High power heat exchanger inside, so heat can be rapidly charged into the heat battery and equally quickly extracted –high rate discharge.

This means can deliver 20+ litres per minute hot water for showers

This means can rapidly warm a heating system (comfort & SAP points)

Modular

Cuboid and able to stack like Lego®

Cost-EffectiveComparable price to Hot Water TanksLower Total Cost of OwnershipMuch lower cost than electric batteries

Sunamp & University of Edinburgh Collaboration: Technical Innovations

Overcame instability of original material <100 cycles before failure

• Patented SU58 >35,000 cycles (so far) ✅

Wouldn’t always solidify (no heat)

• SU58 always solidifies and releases heat ✅

Slow heat transfer (no showers!)

• Heat exchanger inside = high flow rate hot water ✅

Gen 2 Heat

Battery

High Energy Density

Retains PCM compactness when scaling to heat battery size (non-trivial).

-5(23)

0(32)

4(39)

8(46)

14(57)

28(82)

34(93)

43(109)

58(136)

83(181)

88(190)

114(237)

T, °C (°F)

Cold storageAir conditioning

Waste heat recovery & pre-heat

Low temp heat pumpSolar thermal

Hot waterSpace heating

Industrial process heatSteam generation

High temp heat pumpBiomass, gas, propane, oilCHP/Co-Gen

Sunamp Heat and Cool Batteries can be filled with different PCMs to optimise each application

Sunamp PCMs are internally developed, inorganic, non-flammable materials. Values indicate phase change temperature. They are at different level of development and not all commercially available today.

Wide range of Storage Temperatures

-26(-15)

-14(7)

-10(14)

-18(0)

-21(-6)

Freezing

Organic Rankine CyclesWaste HeatThermal Buffering

Chiller

253(487)

-15(5)

-25(-13)

117(243)

167(333)

188(370)

Proven via cycle testing – latest results

July 2015January 2018

Courtesy of Dr David Oliver (Edinburgh), Materials Scientist & Dr Kate Fisher (Edinburgh), Composite Materials Scientist at Sunamp

Previously undetectable degradation rate just becoming apparent after ~2.5 years and ~35,000 cycles.

Peak rate 120 cycles/day (5 minute charge, 7 minute discharge & repeat)

Average lowered to ~35 cycles/day due to periods when cycle rig was inactive (e.g. Moving premises).

Further testing expected to confirm trendline.

100% DOD Sunamp

Charged/discharged at ~6C (10x higher power)

Typical Lithium Ion Battery

Electric batteries compared with Heat Batteries cycle life

4000 8000 12000 16000 20000 24000. 28000 32000 36000

What do we need to do with each technology to get 36,000 cycles? ~10 cycles per day for 10 years (high utilisation balancing) or 3 cycles per day for 30 years (e.g. Economy 10 off-peak)

Lithium Ion, cycled to 80% DOD, needs to be replaced 8 times – average capacity 90%; terminal capacity 80%

Sunamp heat battery, cycled to 100% DOD, not replaced – average capacity 97.5%; terminal capacity 95% (tested to date)

CAPEX implication LCOS implicationLithium Ion list price (best) ~£350/kWh / 80% DOD => £437.50/kWh useable over total 9 units to get 36,000 cycles => £3,150/kWh => 8.75p/kWh_cycle

Sunamp heat battery list ~£200/kWh / 100% DOD => £200/kWh useable over 1 unit to get 36,000 cycles => £200/kWh => 0.5p/kWh_cycle

Electric compared with Heat Batteries on cycle life

16x16x

Other Key Parameters

Cost of CAPEX per capacity and LCOS are good measures of how much energy can be transacted for how much money.

But to stabilise intermittent grids as they fill up with wind energy, PV solar, etc;to provide ancillary services to TSO or DSO;to rapidly respond to rising & falling output of a large PV array behind-the-meter to avoid export

we also need low CAPEX for the charging power that can be dispatched. Electrically charged Gen 3 heat batteries do well.

• Trial in seven homes funded by DECC

• Off-peak Economy 10 electricity

• Air source heat pump (2.5-3x COP efficiency)

• Heat Battery compact storage provides time-shift: run heat pump when its cheap, use heat/HW at any time

• Easy retrofit installation

• In service for 5 winters (some still with Gen 1 heat batteries, some upgraded to Gem 2)

Heat Pump

SunampStack

Central Heating

Hot Water

Proven by long duration trial (2013 to date)

Results and Benefits:

• typical running costs savings range from 45% to 57%

• carbon emission reductions range from 17% to 36%

This is a 2-bedroomed housewith 2 working occupants.They are heavy hot waterusers having 2 deep baths inthe morning and 2 deepbaths in the evenings

Annual Savings on Heat and Hot Water

kWhsaving

Bill savingCO2

Saving

59% 56% 29.1%

8,404 KWh £602.171259

KgCO2

CASE A – From Electric Heat and Water

This is a 3 bedroomedhouse lived in by a youngworking couple, their heatand hot water usage isnormal. This householdhad night storage heater.Comfort has improved.

CASE B – From ETS and Electric Hot Water

This is a one-bedroom house,semi detached bungalow.The occupier is an retiredman who looks after hisgrandchildren in the earlyevening so the house must bewarm - Achieved

Annual Savings on Heat and Hot Water

kWhsaving

Bill saving

CO2

Saving

49% 57%Not Available

3,291KWh

£325.91Not

Available

CASE C – From Electric Heat and Water

This is a 5-bedroomedhouse with 2 workingoccupants, 1 teenager and 1visiting young adult.Previously mains gas heated

Annual Savings on Heat and Hot Water

kWhsaving

Bill savingCO2

Saving

77% 50% 46%28,476KWh

£926.773645

KgCO2

CASE D – From Gas Heating & Hot Water

Annual Savings on Heat and Hot Water

kWhsaving

Bill savingCO2

Saving

40% 45% 36%

4,921KWh £414.781596

KgCO2

Trial Results

Spec40 kWh Sunamp heat storeAir Source Heat Pump (Daikin)Works to -25C

Proven via large scale trial

Over 1000 tenants positively impacted with 20%+ bill and energy savings

766 Gen 2 Heat Battery Products installed in over 600 homes by Q1 ‘2016

4.4 MWh total storage in 2028 Heat Battery 'Red Cells'

In daily service for two years with high reliability providing heat and/or hot water to circa 2000 people

Products developed and manufactured by Sunamp near Edinburgh

maurizio.zaglio@sunamp.co.uk

Electric battery compared with heat battery

81% final household energy consumption is heat

130mm38kg

26.5dm3

2.5kWh35kW

>35,000 cycle life(to >95% capacity)

16% final household energy consumption is electricity

Appliances 12%Lights 4%

Cooking 3%

% household final energy consumption in UKUnited Kingdom housing energy fact file, 2012

Sunamp Heat BatteryBYD Lithium-ion battery

Space heating 62%Hot water 19%

30.7dm3

2.5kWh2.5kW

6,000 cycle life (to 70% capacity)

Smart heat batteries

Shrunk 4 times smaller

Smart interaction with grid &behind-the-meter renewables

Customer engagement

Hot water Space heating

Space cooling

Hot water tank

Gen 3 heat batteryThesis: Aggregates of heat batteries in just hundreds of buildings can deliver meaningful capacity (MWh) and power (MW) to balance the electric grid while supplying all needed heat and hot water.

PV or ST

Fossil Fuel or Biomass

Boiler

Solar EnergyGrid Electricity

PV DC Electricity

Thermal

Third Party HVAC CompatibilityBoiler (Gas, Combi, Oil, Biomass, …)Heat Pump (Air, Ground, Water, …)Controllers (Nest, Honeywell, …)Solar Panels (PV or Solar Thermal)PV AC Controller (Power Diverter, Solic 200, …)

Heat Pump

Sunamp ControllersUniQ System ControllerUniQ PV DC ControllerUniQ PV AC ControllerSunampOS (DSM)

Heat Battery OptionsCapacity (3, 6, 9, 12, 60 kWh)AC or DC elements (various kW)

InverterPV AC Controller

Mains AC Electricity

PV AC Electricity

Natural Heat

Heat and/or Hot Water

Preview of Gen 3: Widest range of Applications

Launching Q1 2018

PV or ST

Solar EnergyGrid Electricity

PV DC Electricity

Thermal

Heat Pump

InverterPV AC Controller

Mains AC Electricity

PV AC Electricity

Natural Heat

Heat and/or Hot Water

Supporting the electricity Grid

Reducing Demand PV self-consumption – absolute reduction

Use of Heat Pumps – relative reduction – typically COP 3 (1 unit of electricity gives 3 units Heat)(Sunamp / DECC / BHA trial results:• 45 – 60% energy and bill reduction)

Flexing TimingDrawing electricity only at low-carbon times (National Grid API predictive)

Even ‘simple’ off-peak like Economy 10, with only resistance electric heating and low Sunamp heat loss, gives benefits of enabling more intermittent Renewable electricity into the Grid (and reducing demand for dispatchable coal and gas)

Is there a missing piece?

Transmission System Operators

(TSO)

Distribution System Operators

(DSO)

Aggregator (e.g. Open Energi)

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Aggregator (e.g. Open Utility)

Aggregator (e.g. Vcharge/OVO))

Micro Aggregator

SunampOS• Runs in its own processor with memory,

security and communications • Links via API to the Heat Battery controller

for state of charge, state of health and to issue commands (e.g. “Charge now at 7kW“)

• Aggregators can plug in their own Apps via an API to offer their services (the world doesn’t need another aggregator) and aggregate up hundreds of small units securely to their larger aggregation scale

• Delivers user functionality like statistics, metering, control

• Sunamp are inviting partnerships around this needed piece with other vendors including aggregators and energy storage companies e.g. Electric batteries

Aggregator 1 Aggregator 2 Aggregator 3

Sunamp Highlights

Sunamp Heat Batteries are probably the world's most energy efficient Thermal Stores – disruptive to hot water tanks, complementary to HVAC equipment, electric batteries, renewable energy & intermittent grids

Cost parity with water tanks today with performance superiority.

Much lower ‘cost per MWh’ and ‘cost per MW’ than lithium-ion batteries (for Heating and Hot Water applications)

17 patents granted, 74 in pipeline across all key countries – materials, heat battery, system, applications

DECC funded trial of Gen 1 Heat Battery systems in 2013 (still in use today)

Over 900 systems installed using Gen 2 Heat Batteries (trial and private sale)

Gigafactory manufacturing capacity coming online for Gen 3 (1 GWh per year)

Conclusion

Top 3 key learnings or takeaways1. What is a Heat Battery?

• A highly competitive energy storage that addresses the largest demand (heat) and provides flexibility of charging (electric)

2. What is the benefit of making Heat Batteries smart?• Aggregate flexible electric demand to solve the

heat and electricity conundrums

3. Cost benefit analysis of Heat Batteries compared with other energy storage for balancing electric grids• CapEx and LCOS benefits against market leaders

in range 2x – 32x depending on your criteria (MW, MWh)

• Many heat batteries will be installed for “normal” HVAC reasons, e.g. Provision of hot water, so over-sizing slightly to provide flexibility is even less expensive

Solution Statement

• Can we be smart and harness electricity and heat intermittences via something (say a smart heat battery) to solve both together?• Sunamp believes an emphatic Yes

• We are prepared to work with partners (several in play already)

• SunampOS will deliver a flexible, no lock in solution that is aggregator friendly

andrew.bissell@sunamp.com@sunampltd

01875 610001

Optimising Electrical Systems via Smart Heat Batteries

Presented at

Energy Storage and Connected Systems 7th February 2018