If You Want To Think About Green Energy You Should Start Thinking About Energy Storage

Energy is one of the key parameters to secure our lifestyle and stay in a comfortable home (and country). The development of energy systems is facing several questions at the moment:

• How can we protect our environment regarding energy development systems?
• What are the lessons learned from previous incidents in Nuclear Power Plants?
• What are the solutions to optimize energy cost in the winter season (Energy efficiency)?

The energy grid needs to be more optimized and manageable to save on energy bills and help in terms of social welfare.

The traditional state (first level) of energy grid consists of the production of energy from different fuels to satisfy the private client’s consumption and also the industrial demand. This system manages to deliver the energy produced directly to the clients with transmission lines from the distribution site to the final customers.

The second level makes it possible to introduce energy storage systems to the grid management operations to equalize the consumption/demand with the power produced. Another option of energy storage is to manage international grid connections regarding peak hours productions and energy price (Levelized Energy Cost).

Europe needs energy resources to diversify its energy portfolio. However, energy cost depends hugely on oil and gas prices that continue to increase depending on the stock market, political situations, and conflicts. Because of these fuels, the price of energy is unpredictable and it’s not possible to have a fixed amount of energy resources.

The energy strategy management is based on three main parameters as shown below:

The security of supply is more related to the diversification of energy resources. According to the multi-criterion analysis from IIASA organization, the energy dependence is going down according to the investment to diversification, meaning we could reduce energy costs by 50% from today to 2100.

How can we reduce the energy price?

Nowadays, several energy storage systems exist:

• Flywheel,
• Compressed Air Storage, and
• Pumped Storage Systems.

The Pumped Storage System (PPS) shows very interesting environmental and economic advantages. This technology uses two reservoirs to balance energy storage and production. However, when energy storage is needed, water is pumped from a lower reservoir to the upper one, this operation is also needed in case of grid interconnection for a pricing strategy.

The energy stored depends on two main parameters: The height and reservoir capacities. The site with an elevation of more than 100m is more suitable to construct PPS because we can reduce the cost of construction. Corresponding to the equation E=QgH (E = Energy, Q = water flow, H = height), increasing the height by 10% results into decreasing the reservoir capacity by 5%.

Seawater Pumped Storage

Another alternative of the lower dam is to use the sea. This way we can reduce the cost of reservoir construction and then have a short payback time of PSS. Sea is considered as the unlimited reservoir to store energy and availability near to cliffs.

One available project in the market is “Okinawa Project” for 30MW capacity.

Fig. 1: Okinawa Seawater Pumped Storage (Image via Google Earth)

The seawater pumped storage system will be a good solution to store energy. But this type of project can present some biological effects such as the seepage of the seawater, impacts in the fauna and the stability of structures.

A different seawater pumped storage system configuration can be imagined. We have underground and normal pumped storage systems. An underground system is more profitable near the cliffs for maintenance reasons. However, with an underground system, we can protect the penstock for different weather conditions better and have a secure system.

The use of seawater pumped storage system is more profitable for Islands energy market portfolio. However, the offshore projects are more profitable for islands as we have the availability for wind energy and use the sea as a resource for hydropower systems.

Energy Potential In Europe

For Europe, we have huge available capacities and sites to use the sea as a lower reservoir. A research guided by the University of Brussels concluded that the north of France and England show very interesting places to implement sea water pumped system. There are

• 28 possible sites in the North of France and
• 23 possible sites in England.

As an example, the Manneville site is shown in the next figure with a huge available surface of 3km2.

By investing on seawater pumped storage, we can reduce the cost of the lower reservoir who depend on the reservoir volume by the following:

Ccout = 9161V^0.54+ B
(B is the land cost)

Reducing cost of energy storage helps to achieve national energy strategies according to local market constraints. Another added value for this system to use the storage water for desalination and then combine two work strategies (energy storage and desalination) with a reasonable cost energy storage system.

The development and investment in seawater pumped storage systems could be interesting in the case of offshoring wind project especially in the North Sea region where wind speed is more important to have a good amount of produced power.

The optimization and management of the electrical grid are more complex without an efficient energy storage system as energy is not an instantaneously stored parameter. One European market challenged by green energy is the Canarian Island market. However, the Islands launched Green Power Project by investing in offshore wind production and seawater pumped storage system.

Microeconomics Value Of Green Energy

By investing in renewable energy systems we can add a new value for our European citizenship and also secure our energy portfolio. We can add a new value of our research and development system by investing in the development of new turbines and pump materials for high speed and heavy operations.

We create new markets for large companies and startups to work together. However, in the case of energy storage, startups can contribute to small-scale PSS and develop their own solutions to deliver to companies and private customers. In case of seawater pumped storage, research, and development can focus on subjects like:

• Corrosion and power plant lifetime regarding seawater as fluid
• Development of a floating production room
• Optimization of the smart grid connections

One example for a small hydropower power plant is the project developed in Liege (Belgium) by the Nethys Energy Company to produce 20000kWh per year.

The future development of Europe’s energy sector will be redirected to diversify energy resources and use it in a meaningful way (rational use of energy). Our goal will be to introduce some new concepts for energy transition and decarbonisation for a better environment.

__________

Sharing is caring!