We are renewing and building infrastructure to deliver tomorrow's smart, sustainable energy - helping everyone to reduce their impact on climate change.
We need to cut our own impact as a business, at a time when the demands of network investment mean we must buy more goods and services, more resources and materials. This will inevitably increase our environmental impact as well as the greenhouse gas emissions generated by our supply chain on our behalf.
We are committed to measuring these emissions, and reducing them relative to our investment and growth. At the same time we are working on our UK networks to reduce greenhouse gas emissions from burning fossil fuels and the release of sulphur hexafluoride and natural gas.
Overall we are committed to reducing the greenhouse gas emissions from our processes, operations and offices by 80 per cent before 2050, with an interim target of 45 per cent by 2020.
Heat Pipe at Grain
The Isle of Grain Liquefied Natural Gas (LNG) Terminal uses waste heat from the adjacent E.ON power station to reduce its own demand for fuel gas, potentially saving up to 300,000 tonnes of greenhouse gas emissions each year - the equivalent of taking 100,000 cars off the road. LNG imported at National Grid's terminal on the Isle of Grain has to be vaporised before it can be exported into the UK's gas supply network.
This process can consume up to 1.5 per cent of the imported LNG as fuel gas to vaporise the LNG.
By working collaboratively with the local E.ON power station, National Grid installed 3km of pipeline to transport waste hot cooling-water from the power station to the Grain LNG Terminal, and return cold water to the power station - thereby substantially reducing the demand for fuel gas.
The power station is able to provide up to 227 Megawatts of waste heat via the pipeline every day, providing around 90 per cent of the heat energy needed at the Grain Terminal.
Recovering Waste Heat
Heat pumps have been installed at the National Grid substation site at Hurst to take the waste heat from supergrid transformers and use it to heat offices.
Transformers at substations reduce the voltage of electricity to allow it to be safely distributed around the energy networks – in doing so, the transformers get warm. Cooling systems stop the transformers getting overheated but currently the waste heat is lost.
National Grid operates over 200 substation sites across the UK and there are environmental and cost benefits to be realised by putting this waste heat to good use. It’s possible that similar technologies could be applied to put other waste heat to beneficial use.
In 18 months since installation, the project has recovered 64,279 kWh of heat saving £9,000 in heating costs.
At current energy rates, the heat pump investment will pay back in just under 9 years.
Due to the success of this project, this technology is being deployed at a number of additional substations.