In the East of England, we’re progressing well with the introduction of more renewable systems and getting off oil and other fossil fuels. Our renewables Project Manager, Dee Nunn, tells us about the new biomass boiler at Sutton Hoo…
This winter, Tranmer House – part of the Sutton Hoo Estate by the Suffolk coast – has ditched fossil fuels with the installation of our new biomass boiler.
Tranmer House was the home of Mrs Edith Pretty when, in 1938, she enlisted the help of local archaeologist Basil Brown to excavate the mysterious mounds she could see from her window. The excavation uncovered an Anglo Saxon ship burial – one of the richest burial sites ever found in Northern Europe!
The Anglo Saxons would have had little choice but to use wood fires to keep themselves warm but Tranmer House has moved to wood fuel in a much more high tech way!
Running on sustainable wood pellets, the boiler has been installed into an outbuilding thought to have been a former coal store. We had to make a few subtle changes to the building to convert it to a biomass plant room including adding a new chimney specially designed to match the existing one and the addition of delivery pipes for the pellet to be blown into our 16 tonne fuel store.
Unfortunately the Sutton Hoo estate does not produce enough wood to allow us to grow our own fuel like we are doing at other properties in the Trust such as Ickworth house. Our pellet will be sourced from sustainably managed woodlands in the UK and, because pellet is much denser than wood chip, we can minimise the number of deliveries we will need each year reducing the fuel used to transport it.
1. Wood pellets are fed from the fuel store into the boiler combustion chamber using a screw auger where the fire is automatically started and maintained.
2. Water is passed through a heat exchanger over the combustion chamber which absorbs heat.
3. The water is stored in massive thermal stores which hold 4400 litres of hot water up to 85C.
4. When heat or hot water is required in each of the five separate heating zones in the house, the control systems open valves and run pumps to transfer heat to the relevant heat exchangers through an underground heat main.
5. The boiler automatically clears its ash into two metal boxes and will email us when they need emptying.
Our biomass boiler is the second phase of the renewables programme at Sutton Hoo following the installation of 174 solar panels to the visitor centre roofs in January 2016.
The installation was part of a corporate partnership arrangement between the National Trust and Panasonic. Having been in place for nearly a year, these panels have exceeded our expectations generating over 48MWh of electricity – that’s the equivalent of the average annual electricity consumption of 14 UK homes.
Sutton Hoo is challenging itself to heat even more of the estate with renewables – watch this space in 2017!