Energy Storage

Kari Laasonen*, Tanja Kallio, Maarit Karppinen, Pertti Kauranen

Department of Chemistry and Materials Science, Aalto University,

Finland

There are several needs for energy storage

https://www.iea.org/publications/freepublications/publication/TechnologyRoadmapEnergystorage.pdf

Most of the energy storage technologies are not mature

These include Flow battery and Hydrogen

At the moment the pumped hydroelectric is really used. (Not very

relevant to Finland)

Batteries• Li-ion batteries are getting cheaper due to mass production (Tesla

GigaFactory)

• Chemistry is quite ready. In Aalto new development for the anode materials.

• The Li-ion batteries are still expensive but

• This could drive down the cost of electric cars that use Tesla's battery

technology such as the Toyota RAV4 EV and Tesla Model X which

announced for 2014 to $190/kWh by 2016.

• 2014 manufacturers were already offering battery packs with a cost of

about $300/kWh

Flow Batteries

– Huge batteries where the energy is stored to a metal solution

– Convenient for large scale storage (storage capacity 25 Wh/kg)

– Often vanadium ions (vanadium is expensive)

– In Aalto we investigate Cu ion Flow battery

– The cost estimation of this battery is 200$/kWh in early state and even

100$/kWh at large scale production state

– The organic aqueous flow battery is expected to cost 180$/kWh once the

technology is fully developed (http://dx.doi.org/10.1002/aenm.201501449)

A 1 MW, 4 MW·h (14 GJ) UniEnergy Technologies

Energy Storage system (Uni.System) owned by Avista

Utilities and installed in Pullman Washington in April

2015.

Costs

Estimate at 2016

Hydrogen

• Fuel cells exist – They are expensive, due to the Pt as catalyst

– High energy density, fast to refuel, high pressure gas require complex infra structure

– In Aalto we have developed new non-Pt catalyst for fuel cells. Motivation: The present Fuel cell require ca. 0.5 g Pt per kW, or 50 g Pt per 100 kW vehicle. At present, around 200 tons of Pt are produced each year. So using current technology, only 4 million cars could be produced.

– About 1/3 of the Fuel cell cost comes from the Pt

– Their mass production has not started.

– The next generation FC’s may be ready at 2030

Fe-Carbon based Hydrogen catalyst developed in Aalto

• Most of the energy storage methods are still expensive (should be 90 -160

$/MWh)

• This target is probably realistic with todays ideas – they need to be made

as products

• We need energy storage if we want to increase the solar and wind energy.

• Germany set a new record on May 11. 2014, by getting nearly three quarters of its electricity from

renewable sources during a midday peak. Nonetheless, Craig Morris says the resulting negative

prices are both good news and bad news

• The so-called spot price of electricity in Texas fell toward zero, hit zero, and then went negative

for several hours. (Sept. 2015)

• There will be more and more “free” energy which need to be stored.

• May be the storage cost will be the major cost of energy in future.

Questions?