The mill’s roof-mounted solar panels and the water turbines, which harness energy from the river, provide almost all of the power for the mill and the café. A boiler that uses sustainably-sourced logs from the surrounding woodland heats spring water for the café. Food waste is composted on site and resident tiger worms are used to compost waste from the toilets.
This system allows us to operate without a connection to the outside world for energy, water and waste.
The challenges
With no connection to the National Grid, energy is stored in batteries for when it's needed most. These are the nerve centre of the renewable energy system.
Just like household rechargeable batteries, they lose their ability to store as much power over time, and at times there’s been insufficient power to fully run the café.
At times we were unable to serve hot drinks in winter or ice-creams in summer. For a site enjoyed by thousands of visitors every year this was a problem.
How we worked with BMW i to improve technology
Like us, BMW i are inspired by the power of nature, and are championing sustainable innovation with their range of electrified cars. Through our partnership they helped the Trust make our places more sustainable, and their funding enabled vital improvements to the energy system at Hardcastle Crags.
The modernisation work, carried out by the original installers, included the replacement of the original battery storage system. This new battery bank gives us 30% more storage capacity. The three inverters were also replaced and reconfigured.
With thanks to BMW i, we can now make sure that we’re able to offer the full café menu on cloudy days or days when river levels are low. It also means that we can run more events and ensure stability for the future.