Microgrids & Smart Microgrids
What is a Microgrid?
A microgrid refers to a localised energy system that has the capability to disconnect from the main grid and function independently. Although microgrids typically operate while connected to the grid, they have the flexibility to switch to their own on-site generation, ensuring uninterrupted power supply in the event of grid outages. This ability to isolate from the grid enhances reliability and resilience, benefiting the site or community it serves.
Within a microgrid, on-site generation can come from solar panels, wind turbines, combined heat and power, generators or other sources of generation. Many microgrids supplement their on-site generation with a battery energy storage system, allowing varied electrical generation sources to be better managed and optimised. Increasingly, microgrids also incorporate EV charging, a high-demand technology that needs careful planning in terms of generation and storage to ensure that sufficient power is available within the microgrid.
A Microgrid is defined by 3 main characteristics. They are Local, Independent and Smart.
- Local: – A Microgrid creates energy for customers within a small area instead of the large centralized grid. By generating locally this eliminates some of the losses which occur during transmission.
- Independent: – A Microgrid should work independently from the national grid which gives its users added energy resilience during a blackout.
- Smart: – A Microgrid needs intelligent energy management software to be able to seamlessly switch to local generation from centralised generation in the event of a blackout or to take advantage of Grid Service contracts.
What are the Advantages of a Microgrid?
There are several advantages of microgrids, including:
- Reliability and Security: Because microgrids can operate independently and usually have multiple sources of energy available to them they reduce dependence on a single energy source and increase energy security.
- Resilience: Microgrids can help organizations and businesses prepare for and recover from blackouts and brownouts, natural disasters, and other emergencies.
- Energy Efficiency: Increase the use of renewable energy sources by storing the excess generated energy for use at peak times and improve energy efficiency by using advanced energy management systems to optimize the use of available resources.
- Cost Savings: Reduce energy costs by using locally generated energy instead of drawing from the national grid and by reducing the need to transmit energy over long distances which lower transmission losses.
- Environmental Benefits: Reduce CO2 emissions by increasing the use of on-site renewable energy sources and reducing dependence on fossil fuels. Often feeding excess generated energy into the national grid through a Grid Service Contract.
- Flexibility: Through the use of smart energy management software to control the microgrid it can be adapted to the specific needs of an organisation, community, or business and can be expanded over time to include new technologies, sources of power generation, and resources.
- Generate Revenue: Grid service contracts provide an opportunity for excess energy which is generated to be fed into the national grid to generate revenue for your organisation or business.
Microgrid Examples
Railway Station Microgrids
In this Microgrid example, a Powerstar BESS is supporting our industry partner’s infrastructure to enable fast-charging rails to charge stationary trains. The BESS is charged over time from on-site solar PV generation or via the grid connection. Utilising the Battery Storage in this way reduces the need for an expensive new grid connection and also allows for the site to generate new revenue through National Grid service contracts. Powerstar’s Voltage optimisation system dynamically optimises the inbound power voltage to increase energy efficiency, lower energy bills and reduce damage from overvoltage on electrical equipment. Powerstar’s Energy Management software is used for smart microgrid control enabling power to be directed where it needs to be at the right time. Read more about Railway Station Microgrids
Key
- Blue – The Blue line represents Energy which is being consumed from the grid. This could also be power from the BESS in the event of a blackout toensure critical infrastructure continues to function.
- Orange – The Orange line represents energy which can be transmitted in both directions such as the BESS being charged from the Grid and also transmitting Energy back to the Grid.
- Green – The Green line represents energy which is being generated or discharged from onsite sources such as Solar PV or the BESS itself.
Commercial Site Microgrids
In this example, the Microgrid consists of a Powerstar Battery Energy Storage System, Powerstar HV MAX amorphous core transformer with integrated Voltage Optimisation, EV Chargers supplied by our partners and existing Solar PV Generation. For this project, the HV MAX system transforms and optimizes the voltage supplied from the national grid. The BESS is used to buffer rapid charging of electric vehicles without placing additional strain on the site’s grid connection. The Battery Storage system also allows for excess energy generated by solar PV to be stored for use later at peak times. The BESS can also make use of integrated UPS capability to protect in the event of disruption to grid supply. Read more about Commercial Site Microgrids
Service Station Microgrids
The Powerstar Battery Energy Storage system in this example underpins the ability to fast charge multiple electric vehicles at the same time without requiring an expensive increased grid connection. Without battery-buffered EV charging provided by Powerstar fast charging on a large scale required by a motorway service station such as this would not be possible. An amorphous core low-loss transformer and voltage optimisation system dovetails with the BESS system to reduce energy losses and reduce energy bills. The BESS also allows for exporting energy to the grid through grid service contracts. Read more about Service Station Microgrids
Data Centre & Hydrogen Service Station Microgrid
Powerstar Battery Energy Storage system with UPS is paired with longer-term backup utilising SOFCs (Solid Oxide Fuel Cells) to protect the site from both short-term and long-term disruption. In the event of a blackout, the Powerstar BESS seamlessly switches over to provide emergency power for this Data centre to ensure data is not lost and provides time for long-term backup to kick in. A Powerstar HV-MAX combines low loss Transformer with voltage optimisation to reduce energy losses and the data centre’s energy costs. Read more about Data Centre Microgrids
how do microgrids work?
A Microgrid is an energy system which can be run independently of the main national grid. As their name suggests they are usually small scale and will include a combination of elements including on-site energy generation and storage.
A common example is a business with solar PV panels on the roof connected to a Battery Energy storage system (BESS) to enable them to store excess energy which is generated to either use later of feed in to the grid through a grid service contract at times of peak load. A microgrid is usually connected to the main central grid to allow the latter to happen and to increase capacity.
Many microgrids also manage additional energy vectors in the form of heating and cooling, balancing any electrical heating and cooling technology with other sources such as heat pumps or biomass boilers. Most microgrids span across campus or neighbourhood rather than a single building, allowing electricity, heating, and cooling to be managed across the various buildings of a university, hospital, business centre or a residential neighbourhood.
By generating power locally, a microgrid eliminates the losses inherent in most centralised grids, including the national grid and distribution networks. This can save between 8% and 15% of total power generated that would otherwise be wasted through transmission losses. The ability to operate independently also protects an entire site from disruption on the grid by entering into island mode. A degree of independence from the grid can also be important when implementing high-demand technologies such as EV charging, which risk your application being turned down if your DNO feels it risks putting too much stress on your distribution network. With a microgrid, these technologies can operate from on-site generation and batteries without needing additional power from the grid.
How are Microgrids Controlled
An intelligent energy management software is required to manage the energy use on a microgrid. Advanced controllers that monitor both the site as a whole, and the external grid, ensure that the microgrid operates as efficiently as possible. It also helps to reduce external energy costs by purchasing and storing power when prices are low, and relying on on-site generation or stored energy during peak periods.
The Energy Management Software, which is sometimes referred to as a microgrid control system, is designed to optimize the operation of the microgrid, ensuring that it operates in a safe, reliable, and cost-effective manner. The control system uses advanced algorithms and machine learning techniques to forecast the demand for energy within the microgrid and to manage the supply of energy from various sources.
How is a smart microgrid created?
The specific aims of a smart microgrid will determine what elements they feature and how they are managed. Typically, there will be on-site power generation, from solar, wind, or Combined Heat and Power (CHP), and multiple buildings or equipment requiring specific power loads at certain times. With the ability to run independently from the National Grid, a microgrid can protect a site from power disruptions and reduce costs and carbon emissions from electricity use.
Whatever makes up the network of generation and loads, a control system is required to manage the microgrid. A smart microgrid will have a control system capable of automatically monitoring, predicting, and controlling the power flows, deciding when best to generate, store, and use the energy available.
Battery energy storage is an integral part of smart microgrids. These allow energy to be stored for use when most beneficial. Energy generated on site can be fully used or sold back to the grid if not needed at a peak price. For organisations that have invested in CHP, battery energy storage allows the CHP to remain operational without power supply from the grid, providing enough power to keep the site running independently and uninterrupted.
Which sectors benefit most from smart microgrids?
The flexibility offered by microgrids makes them a valuable option to a wide range of organisations, regardless of sector. Even those with relatively low demand and complexity could improve power resilience, reduce energy costs, and enhance efficiency by implementing a microgrid solution.
However, microgrids are most effective on large sites with complex energy flows, such as transport, manufacturers, defence organisations, universities and healthcare providers with large campuses or estates. For organisations that require power resilience as well as reduced carbon emissions and the ability to navigate grid constraints, a microgrid can offer a comprehensive and effective solution.
Contact us today to find out how we can support your organisation’s energy objectives