Thursday, April 11, 2024

Powering the future of smart buildings: battery energy storage

Batteries repurposed from yesterday’s electric vehicles could hold the key to sustainability for tomorrow’s smart buildings. Matthew Lumsden, CEO of Connected Energy, explains why.

The sustainability of buildings is a high priority for organisations and will remain so as we move towards Net Zero. Smart buildings can play a key role in reducing an organisation’s carbon emissions however three of the most popular next steps: installing solar panels, heat pumps, and electric vehicle (EV) charging points all come with their own challenges. Most commonplace is the issue of the grid capacity that is needed for implementation and the power requirements they additionally add to a site.

Grid limitations

All buildings have a limit on their electricity usage – this capacity is set by your distribution network operator (DNO) to ensure that other buildings on the same grid connection all get a fair share of the available energy. This means that, if you want to add energy intensive equipment like heat pumps or EV charging, you could need a connection upgrade. This can often run into the hundreds of thousands of pounds and can take months to implement.

Similarly, most sites experience peak demand spikes, meaning that you might only be exceeding your grid connection capacity for short periods each day. In this instance, paying for a grid upgrade could be counterintuitive.

Smarter solar

Solar power offers a cost-effective way to reduce energy bills and cut carbon emissions, a win-win for many organisations. But the real key to delivering a return on investment is optimising its use, which means making sure every kilowatt-hour (kWh) of solar you generate is used by your business. The best way to monetise a rooftop PV array is to offset the site load while exporting as little energy as possible back to the grid. This means identifying the best fit between the site load and the generation profile of the PV. Battery energy storage systems (BESS) enable solar arrays to operate in that sweet spot by storing some of that energy generated for use at a later time.

Through data analysis, experts can model the energy generated by solar panels to demonstrate how a BESS could maximise savings and further reduce carbon. This can be modelling the benefits of storing surplus energy generated from solar, but it can also include how a BESS can help manage load profiles and reduce peak loads on site.

EV charging demand

A great example is EV charging. As buildings move from installing one or two chargers to entire charging hubs, the energy load significantly grows. This can take a building over its agreed grid capacity, leading to surcharges. If those EVs are also charging during peak tariff periods they are also increasing your overheads. A BESS enables you to store energy from solar arrays and use it during peak periods to reduce electricity bills – you can also charge the BESS at night direct from the grid when tariffs are lower and use that cheap energy the next day, offsetting those higher costs. One recent example of this is our work with Nottingham City Council’s innovative new fleet depot where two battery energy storage systems will work together with 40 V2G charge points, solar arrays and a new software system to create a full building energy ecosystem.

Powering heat pumps

In the same way, heat pumps increase the energy load of buildings. They have much lower carbon footprints than gas boilers but require a substantial amount of electricity to power them. If you are already at or close to capacity with your DNO, you can’t add heat pumps without incurring surcharges on your energy bills. A BESS can solve this problem in a much more cost-effective and timely way than paying for a DNO upgrade.

Sustainable second life

BESS can build the business case for solar PV, heat pump installation, and EV adoption. But if they are comprised of new, large-scale lithium batteries then there is still an environmental impact.

However, what if we could create BESS out of existing batteries? This is exactly what Connected Energy has achieved. When an EV reaches the end of its useful life, the batteries still have up to 80 per cent of their energy storage capabilities. Connected Energy takes those batteries to create E-STOR, its 360kWh energy storage systems.

At Connected Energy, we work with organisations to help model whether a BESS could work on a specific site. We model current and future energy data combined with information on a site’s requirements and then use this data to project the costs of various scenarios, with or without energy storage.

Our feasibility studies set out our calculations showing both the financial and carbon benefits of a battery energy storage system. We can even show what would happen if you were to increase renewable energy on site or how it could work with different mixes of EV chargers and heat pumps.

The UK Government estimates that buildings are responsible for 30% of our greenhouse gas emissions. At the same time, UK energy usage is forecast to double by 2050 from a 2018 baseline. This represents a dual challenge for building managers as they look to implement energy efficiency against a backdrop of increasing energy use.

Smart buildings can help on the road to Net Zero. Combining a range of decarbonisation measures with battery energy storage can however lead the way to a more reliable, resilient and sustainable energy future.

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