As we attempt to move away from a world which is powered by fossil fuels, technology is changing at a rapid pace with solutions being developed that will harness the potential of renewable energy sources on a domestic, local and national level. Alongside this is also the idea of the Smart City infrastructure, including energy networks, where digital and telecommunication ‘Internet of Things’ technologies will be interconnected for the benefit of local communities.
Energy storage is one solution that is currently gaining traction towards a greater uptake in both of these throughout the world. As its name suggests, the technology works by storing the energy provided by the National Grid or directly from renewable sources, for use at a time when demand is highest.
One of the developing concepts in the area of energy management for Smart Cities is the proliferation of the microgrid network. As the name suggests, a microgrid is a smaller version of the national energy grid, the main difference being that the microgrid is powered by energy sources, including renewable, that match power with local demand rather than national demand. For example, a microgrid network would connect both small-scale generation, such as solar panels, or large-scale windfarms to any new or current publically-owned building or space within the local community.
However, from the outset there is an obvious stumbling block for microgrid development. If the network became reliant on clean energy sources alone, which may need to be the case as many local councils have set their own targets for lowering carbon emissions, then there needs to be a solution which will address the unreliability of renewables, as if the sun doesn’t shine or the wind doesn’t blow, many vital public buildings will not receive an acceptable level of electricity supply.
Energy supply to meet demand
One of the only ways to harness renewable energy effectively is to use battery-based energy storage technology. When connected to the microgrid, the storage solution will be able to dictate whether the energy needs to be stored for later use, or sent directly to areas of local demand, ensuring public sector energy supply will match demand.
Even with the use of energy storage solutions, sometimes the microgrid may be under significant pressure, with the requirement to draw additional energy from the current National Grid infrastructure. When energy is supplied by both, an energy storage solution can act as the go-between, monitoring the predicted supply and demand of electricity to calculate when National Grid support is needed.
For example, there are currently significant charges placed on public buildings which consume a significant amount of National Grid electricity at high demand periods. These tariffs are unfortunately unavoidable, as each distribution network operator has a local monopoly on the supply of electricity and the charges can account for as a much as 15% of a local council’s energy costs.
By controlling supply, the energy storage solution will ensure all public buildings that are charged for consuming National Grid energy at periods of high tariffs are supplied with electricity from the microgrid network to negate additional costs.
Further benefits from energy storage in the microgrid include reducing costs by programming the technology to control certain isolated aspects of a local council’s electricity infrastructure, such as street lighting, which may be expensive to manage on a traditional National Grid network. The solution also offers full UPS (uninterrupted power supply) capabilities, which will provide up to two hours of guaranteed electricity if all other systems providing power shut down, making it ideal for critical public sector buildings, such as hospitals, which require electricity for life-saving equipment.
Single building storage
Energy storage does not have to be installed within a microgrid network to be considered a viable solution. Storage on a smaller scale can provide any current or new public building with the same benefits, including improving the reliability of renewables, reducing tariff charges and providing UPS capabilities. Also, with the Government significantly reducing the amount homes and businesses are reimbursed for producing energy from on-site renewable sources (FIT tariffs) rates, installing energy storage is now a more cost-effective solution than solar PV or small-scale wind generation.
There is also an opportunity for storage solutions to generate revenue for the public sector by supporting National Grid capacity through DSR (demand side response) schemes, which is provided for any method of assisting reserve, response, avoidance or capacity on the electricity network. Supporting grid capacity through DSR using energy storage can be significantly cheaper than maintaining electricity use through periods of high demand hours. What’s more, unlike diesel generators and CHP units, energy storage systems have the ability to be connected to the National Grid, allowing instant electricity discharge. As a result, the technology will ensure all businesses successfully respond to at least 95% of all DSR demands.
There are a host of microgrids in operation around the world and with the growth of the Smart City concept and Internet of Things-based technologies, the idea of microgrids providing energy to local communities in the UK is not a distant pipe dream.