1 topic, 2 key figures, 3 startups to draw inspiration from
On the one hand, heating and cooling applications are among the largest energy consumers (about half of the total energy consumption). On the other hand, some of the renewable electricity produced is lost due to non-immediate use, and this will continue to accelerate as renewable energy facilities are being developed faster than batteries and storage solutions. The reconciliation of these two issues, converting electrical energy into heat (or cold), is called Power-to-Heat (PtH). Thermal energy is produced by heat pump technologies or electric boilers. In the context of growing environmental awareness, industrials are increasingly looking for technologies that will enable them to shift from fossil-based industrial heating to electrically-based, power-to-heat processes. These industrial heating applications account for almost 20% of global energy consumption.
These renewable power-to-heat technologies help industries to reduce their CO2 emissions and offer higher flexibility in the power system when equipped with smart load management. Industrial application technologies are already mature and commercially available. However, they have yet to be integrated into hybrid heating systems (e.g. with natural gas).
How does it work? The first step is the delivery of electricity from renewable sources to power stations (which may be large centralized heating production stations or decentralized entities). Infrastructures can be equipped with thermal storage systems, such as those of Form Energy, to enable consumers to use the stored heat and thus reduce the demand on the power grid during peak electricity demand periods. Afterwards, there are two technologies to convert electric power into heat: electric boilers and heat pumps. Electric boilers use electricity to heat water, which is then circulated through pipes to provide space heating or stored in hot water tanks for later use. Heat pumps, on the other hand, transfer heat from the surrounding heat sources to buildings and infrastructures. They can fulfill both heating and cooling requirements — typically using between 66% and 80% of the energy contained in the ambient air, water, or ground, and between 20% and 33% electricity to drive the process.
Where is it used? These technologies are applied in different industries, for several uses. The first example is the food & beverage industry, where heat plants are used in Japan for brewing sake and beer. The Suntory production plants, for instance, use a cogeneration system (combined heat and power) that recovers the heat generated from in-house generation and uses it as a heat source for brewing beer and extracting coffee and tea, increasing energy efficiency to 70-80% and reducing CO2 emissions by 20-30%. Another example is the container washing plant in Spain that uses solar thermal heat. 22% of their hot water (80°C) demand is covered by a solar thermal system based on flat plate collectors, and the remainder is covered by a conventional boiler using natural gas. District heating is also a common application of power-to-heat. In Hamburg, Vattenfall operates an electric boiler that uses excess wind generation, thus avoiding wind power curtailment, to generate district heat in Berlin. The units use electricity from renewable energy sources to heat water, which transmit heat to residences and commercial buildings.
More generally, power-to-heat innovations contribute to the transformation of the power sector in 5 ways:
- Reduction of renewable energy curtailment: the excess of energy is used to address heating needs.
- Increased flexibility through load-shifting: heat pumps can offer demand-side flexibility by switching their electricity consumption from high-demand time intervals to low-demand time intervals to convert electric power into stored heat or cold.
- Large-scale energy storage: the surplus heat (resp. cold) produced with renewable energy in summer (resp. winter) can be stored in thermal reservoirs (mainly aquifers), which then can be used to meet the winter (resp. summer) heating demand, thereby reducing the need for non-renewable heat sources during peak times. The most common solution is the use of Phase-Change Materials (PCM), which are efficient against energy loss and leakage and are substances that release or absorb enough energy to maintain a regulated temperature. A great example of such a process is the Canadian project Drake Landing, which uses solar thermal energy and seasonal underground thermal energy storage for a district heating scheme. It supplies a residential community of 52 households that have seen their greenhouse gas emissions cut down by more than 5.5 times per year.
- Grid services provided by aggregators: new “smart” storage heating solutions are designed to take advantage of variations in electricity prices throughout the day and can be remotely controlled by aggregators to both optimize heating costs for consumers and provide grid balancing services to the national grid.
- Increased self-consumption through renewable local generation: consumers with solar rooftop systems can use the locally generated electricity to power heat pumps.
Ultimately, having understood how power-to-heat systems work and what their benefits are, it can be useful to bear in mind the drivers behind their adoption and the regulations that are put in place. Incentives to decarbonize the heating sector are leading to the deployment of heat pumps at a steady pace. On average, the operating costs of using electricity to generate heat are comparable to those of using fossil fuel-based sources. High-performance heat pumps can generate more than 4–5 kWh of useful heat for every 1 kWh of electricity consumed. Furthermore, regulations are being implemented in pioneer countries, like in Germany, where the Renewable Energy Heating Act bans the use of oil burners to heat new buildings and requires all new buildings to use energy generated from renewable energy sources for space and water heating. Similarly, in 2017, Norway’s Ministry of Climate and Environment passed a law banning the use of oils and paraffin from 2020 in heating applications.
To conclude, now that power-to-heat technologies are mature and up-and-running, more incentives should be brought forwards to increase the use of renewable energy in heating and cooling. Domestic and industrial consumers will need to make upfront investments to shift to renewable energy for heating and cooling applications, and schemes that reduce the economic burden on consumers will encourage faster adoption of renewable energy in heating and cooling. However, these schemes need to be tailored to the needs of different consumer segments, types of buildings (residential vs. industrial), and types of heating system (centralized vs. decentralized), as well as to other external factors, such as the climate zone.
2 Key Figures
177 power-to-heat startups
registered by PitchBook, including 100 “thermal energy storage” startups
Market size expected to reach $369M by 2025
The market size of thermal energy storage is expected to reach $369M by 2025, at a CAGR of over 14.4% from 2020.
3 startups to draw inspiration from
This week, we identified three startups that we can draw inspiration from: Malta Inc, Enerstorage, and Heaten
The US-based startup Malta Inc builds an electro-thermal energy storage system that converts electricity to thermal energy for storage. It later converts the thermal energy back into electrical energy whenever required
The German startup Enerstorage sells power-to-heat plants for industries that require a lot of heat. The PtH systems provide an important link between the heat supply and the power grid, regulate the power grids, and thus lead to a successful energy transition.
Heaten is an industrial startup that provides heat-to-power and power-to-heat machines. Their very high-temperature heat pumps are based on an innovative piston machine technology, which provides an output temperature up to 165°C, which covers 30% of the energy demand of all industrial heating processes.