Community Energy & Hydrogen Storage

Germany, the home of?our?forthcoming Enapter Campus?mass-production?centre,?agreed to become largely?greenhouse gas neutral by 2050?by signing up to the Paris Climate Agreement.?Among the many?challenges?associated with?tackling?this?pledge, one?hits?particularly close to home:?the?German?building?sector?is responsible for?more than a quarter?of?the country’s?CO2 emissions.?

Although?energy-efficient renovation measures,?use of?renewable?energy?and?the?replacement of heating systems?have?already?begun to?reduce?building?emissions,?massive savings are still needed.?

Expanding?the generation and use of?renewable energy?is?essential for these?savings, no matter the location.?Using?locally-created energy can?be transformative?here,?particularly?when?paired with?flexible energy storage?from?green hydrogen?–?and especially in networked energy communities.?

Networked energy?communities?

A networked community can be a single?multi-user?building or multiple buildings?with energy infrastructure that doesn’t depend entirely on an external, central supply.?They often?exist with a direct connection between power producers and users?but?without?a?traditional?network operator.?

That makes?producers and consumers effectively?one and?the?same?–?so-called?“Prosumers”.??

The?main?goal of such a community?doesn’t have to be?self-sufficiency; it’s?often sustainable, flexible and economical?energy production.?To achieve?this,?a networked community?first needs?an operator for energy production, storage and distribution. This could be a community of Prosumers (citizen energy), apartment building?owners, housing cooperatives or?regional energy?suppliers?(among others).?

Photovoltaics?(PV)?is?also?a?fundamental?tool?for?many?communities, and?the potential for?building-integrated solar?in Germany alone is estimated?at?a?huge?1 TW by Fraunhofer ISE.?To put that into perspective, the?total installed global solar capacity?at the end of 2020 was about 0.7 TW.?PV?brings the creation of renewable energy closer to the user?but also creates?some?challenges to overcome.??

Tenant?electricity?and the storage conundrum?

When?owners of apartment buildings install?rooftop?PV modules?and offer renters the power?via an in-house network, it’s?a networked energy community model?known as “tenant electricity”.?Excess?power?can be sold to an electricity supplier?or?extra?energy can be purchased.?

Such?communities?are becoming more popular around the world, with Germany looking to?boost?their growth?through?increased surcharges?paid on?such?power through its tenant electricity scheme. Moreover, the?Technovio?report “Global Rooftop Solar market 2020-2024” states that the?global rooftop solar market?is?expected to grow?by 11.36 GW between 2020 and 2024.?

But?solar power?generation?and?its use?often?aren’t?simultaneous, which can lead to?curtailments?when energy can’t?immediately?be?disposed of.?Selling the power?also?isn’t?necessarily?the best?option?given?the?decline in feed-in tariffs?paid.?Another challenge:?PV?only produces?power during?the day.??

If?a?community?wants?to produce the?most?electricity?possible, use?it?as effectively as?it can?and?buy?less, then it has to be stored temporarily.?Here’s where?community energy storage comes into play.??

Store energy,?double self-sufficiency rates?

In its?2017?Netflex Study, the German Energy Efficiency Agency (DENA)?concluded?that?maximising?energy?self-sufficiency?is the?most economical?operating strategy for?smart neighbourhoods.?Installing?a storage system leads to?an approximately?doubled?energy?self-sufficiency?rate, helping to?avoid?state-induced electricity charges, levies and taxes,?and?delivering?better?cost effectiveness.?

Even better,?optimised usage of storage systems helps avoid the wasteful?curtailment of?solar energy. More renewable energy can be produced and used at a later point in time.??

But it’s not just the operator who benefits from the community energy concept: The users also?win?when energy production, storage and?distribution are undertaken?by an operator in-house.??

They don’t have to make any initial investment?or?long-term rental?payments, don’t have to take care of their own PV systems and can leave all administrative and legal obligations to the operator. Moreover,?they can enjoy lower energy prices?since they avoid?state-induced?charges.??

Green?hydrogen?energy storage??

The benefits of community storage are obvious?and although many?kinds of?solutions are available,?they mainly?differ in storage duration and storage capacity.?Choosing what?technology?to use?is today?less of?a question of feasibility?and?rather one of?features, project requirements and cost structures.?

Using green hydrogen for energy storage in a community?offers various approaches for?coupling sectors of a networked energy community:?It can be reconverted into electricity using a fuel cell and the?resulting waste heat?created, both from the electrolyser during hydrogen production and from the fuel cell during reconversion, can be used directly onsite in the community buildings.?

Hydrogen?created?onsite?in networked energy communities?can, of course,?be used in reconversion?but also for the refuelling of hydrogen vehicles.?Above and beyond this,?hydrogen storage allows for?larger?amounts of energy?to be?stored over longer periods of time, allowing for the bridging of, for example,?times?of low solar energy?production?over winter?(“seasonal balancing”).??

?By now, these benefits are no longer just theoretical but proven in practice.?

Energy Centre of the Future?

The?Phi Suea House?multi-building development in Chiang Mai, Thailand,?in 2015 became the?world’s first self-sustaining multi-house residence powered by a hydrogen-based clean energy system.?Since then, hydrogen storage solutions for energy communities have advanced all over the globe.?

Jumping forward to?May 2021,?the?German real estate firm?Vonovia?inaugurated?its?“Energy Centre of the Future”?in Bochum-Weitmar, a glass-clad?technical?centre?including energy production,?storage?and distribution systems. Located?in the middle of one of its housing estates?– the “Innovation Quarter” –?the energy centre?delivers?renewable?power?and CO2-free heating to?81 homes.??

Our?AEM electrolysers?for the production of?green?hydrogen?are among the?key?technologies driving the energy centre,?in addition to?fuel cells and heat pumps. Together,?they?supply?households?up to 60% self-sufficiently?with?decentrally-produced,?CO2-free warmth.?Vonovia?already generates 25% of the electricity it needs for this locally from its own PV systems on the roofs of its buildings.??

?Take a?tour?through the Energy Centre of the Future?here.??

Community hydrogen for warmth and industry?

Once?community energy is?converted into green hydrogen,?it doesn’t?necessarily have to be reconverted to?electricity?with fuel cells?to be?used.??

In Rozenburg, a Dutch town close to Rotterdam,?green hydrogen?created by eight AEM Electrolysers?is directly combusted for heating in innovative boilers designed specifically for this purpose.?As a joint initiative from the network operator?Stedin, the municipality of Rotterdam and housing cooperative?Ressort?Wonen, the partners are?investigating the entire production, distribution and conversion chain?for residential heating with hydrogen.?

Another?emerging?approach is making?green hydrogen from excess energy and selling this directly?to industry, where fossil fuel-derived hydrogen is?a?commonly-used?input?in need of?replacement.?

?This approach has been adopted?in the?“Climate-neutral urban quarter – New?Weststadt?Esslingen”, a sustainable showcase community in the?southern?Germany city of Esslingen am Neckar, which opened in June 2021?with 450 apartments, office and commercial space,?and?a university building?also planned.?The quarter uses excess solar energy?from local PV panels and?external renewable sources?to create green hydrogen, the majority of which will be?piped to a filling station. Here, it can be?loaded into trucks to be transported to customers in the industrial or public transport sector.?

?Alternatively, the?quarter’s?green hydrogen can be put into the gas network via a feed-in station, and a hydrogen tanking station for H2-powered vehicles will also arise?at a later stage.?

The drive to community energy storage?

In terms of technology, nothing stands in the way of the broad implementation of community energy. All of the necessary components exist?and will only become?cheaper?in the coming months and years.?Such concepts won’t just?gain?focus due to their environmental?clout but?will?also?attract interest for purely?economic?reasons,?especially?for?multi-use concepts with green hydrogen.?

Hurdles?still?exist in legal regulations for?energy?communities. In Germany,?however,?these?are?poised to make?storage and consumption of self-produced energy?more attractive than selling it back to the grid?for many?community and private solar power producers.?This is true even for individual houses,?as some of?our partners are proving?with?hydrogen energy storage?(article?in German).??

Just as producing?power at home?and selling?it?to the grid?took off?at the start of?Germany’s energy transition?in 2000,?momentum is building?for?local energy?production?to?be redirected?towards personal utilisation?–?unlocked by?energy storage?vectors?such as?green hydrogen.?

You can find?more?hydrogen energy storage?use cases on our website?– as well as the?integration partners?installing?them.??