New technology paves the way for optimal use of renewable energy in tomorrow’s energy system

The growing demand for renewable energy creates massive challenges for the energy system of the future. Greater flexibility and the ability to adjust our energy consumption in accordance with the prices on the electricity market are just some of the new demands that tomorrow’s energy system has to meet. In the BioCat project, supported by ForskEL, a new power-to-gas technology enabling the required flexibility of renewable energy and thus ensuring optimal use of solar and wind energy, is being developed.

As a partner in the BioCat project, The Danish company Neas Energy takes part in ensuring that supply and demand in the electricity grid is balanced at all times and in the best possible way, so that it matches the fluctuation that characterizes renewable energy. The technology developed in the BioCat project makes it possible to convert excess electricity from wind- and solar to biomethane, which can then be stored indefinitely in the existing natural gas pipelines. By storing the converted energy, power plants can apply gas created from renewable sources in order to secure a stable supply of electricity and heat – even when the sun is not shining and the wind is not blowing.

An electrolysis system, which produces hydrogen, is used to convert electricity from the renewable energy sources to the sustainable natural gas. The innovative technology in the BioCat project transforms the hydrogen into biomethane by using a certain kind of bacteria – archaea – and CO2. The biomethane can then be stored and transported in accordance with the demand in the electricity grid.

Sustainable energy at competitive prices

There are several reasons why it is important to develop the power-to-gas technology and apply it in the energy system. One of the main reasons is that it is both easy and inexpensive to store gas for a long period of time. As opposed to other technologies that only manage to store electricity for a very short period of time, gas therefore works as a very important long-term storage option. The biomethane can be produced by means of cheap electricity when for instance there is a lot of wind power or electricity from photovoltaic panels. That way, biomethane is produced from renewable energy, which means that cheap and plentiful electricity can be used when it is windy outside or the sun is shining from a cloudless sky. Therefore, the BioCat solution is very attractive compared to already existing commercial solutions for the implementation of renewable energy in the existing natural gas pipelines.

With this new technology, it is possible to offer sustainable energy to consumers to a greater extent than ever before, and at the same time speed up the implementation of renewable energy into the existing natural gas pipelines. Thereby, the BioCat project enables an energy system where fossil natural gas is replaced with bio-natural gas – a development, in which Neas Energy sees great potential:

Neas Energy is interested in learning about technologies that can potentially become part of the energy system of the future. Such knowledge can ensure that we are at the forefront of the development, which helps us prepare our customers for the newest tendencies in the energy markets as well as adapt our services in accordance with the market development,” explains R&D Project Manager, Lotte Holmberg Rasmussen and continues: “A power-to-gas solution, such as the one demonstrated in the BioCat project, needs someone who is responsible for balancing the power grid, and who can handle reporting of plans and trade with electricity in the electricity markets. If more of these facilities are implemented in the future, Neas Energy is prepared to handle that responsibility.

Consequently, Neas Energy considers power-to-gas to be one of those technologies that can potentially play an important role in balancing the Danish energy system in the future.

Today, we are very much dependent on domestic production and foreign connections in order to balance the supply and demand of the electricity, but in situations where foreign connections fail, it is important to have domestic consumption capable of regulation – that is the only way can we ensure that there is always electricity in the socket, says Lotte Holmberg Rasmussen.

Secure supply of sustainable energy

The construction of the power-to-gas facility at the wastewater treatment plant in Avedøre, Denmark, has already begun. Here, the cutting-edge technology, which enables wind and solar energy to be stored in accordance with the demand in the power grid, will be demonstrated. The commercial-scale facility for demonstrating power-to-gas is very flexible and thereby capable of providing the necessary services for balancing the power grid.

The power-to-gas facility, which is installed in Avedøre, is very flexible as the electrolysis unit has a very low response time and a large storage capacity while the operation is – in principal – only limited by market prices. This flexibility is interesting for Neas Energy, as it creates the opportunity to move the consumption in accordance with the prices in the market and thereby create value for our clients, says Lasse Helleskov Ravn, Business Developer at Neas Energy.

Based on Neas Energy’s knowledge of the European electricity market as well as many years of experience handling both production and consumption units in different electricity markets, Neas Energy will decide the optimal trading strategy for the power-to-gas facility in relation to relevant electricity markets – and be in charge of the trade of physical electricity and reporting of consumption plans.

A need for changed conditions

By participating in different balancing markets, flexible consumption units such as the power-to-gas facility can contribute to ensuring a secure supply of electricity in the electricity sector, which is for the benefit of the individual user.

When a larger electricity production from fluctuating sources is implemented in the energy system, there is an increased need for capacity that is capable of balancing the production and consumption.

From a systems perspective, the power-to-gas technology is important in terms of balancing and long-term storing of renewable energy. New technologies are often challenged economically, which also applies to the power-to-gas technology demonstrated in the BioCat project. It is a political question whether you want this technology as part of tomorrow’s energy system, because at this point, changed conditions are necessary in order for it to be profitable to invest in such a facility. Consequently, the largest barrier is economic, and whether there is political backing to support the power-to-gas technology and its implementation in the energy system, explains Lasse Helleskov Ravn.

Demonstrates the potential of electrolysis systems 

The electrolysis system, which is the electricity-consuming unit in the power-to-gas facility, will be remotely controlled by NEAS Energy by installing communication equipment connecting NEAS’ software-system and the SCADA-system of the electrolyser. At the same time, frequency measuring equipment and frequency regulation equipment is installed, so that the system can be regulated based on the frequency of the electricity grid.

The headquarter of Neas Energy in Aalborg is manned around the clock and from here, an operation controller can at all times control the BioCat facility – for instance by sending an on-signal to the facility in the hours where the unit is accepted in the frequency markets. That way, the equipment ensures that the electrolysis system regulates in accordance with the frequency. In those hours, where the electrolysis unit is not accepted in a frequency market, an off-signal is sent, by which the system no longer regulates in regards to the frequency of the grid.

The potential for applying the electrolysis system for frequency regulation is demonstrated as part of the project. Technically, there is nothing to hinder the facility in delivering the service, as the electrolysis system has a low response time. If this is the case, the market prices decide which balancing services the facility will deliver after the demonstration phase.