The Rookery Farm Biomass Boiler

The Rookery Farm Biomass Boiler

At Rookery Farm, we are very excited to say that hot water and heating is now provided to seven of our properties by our recently installed Biomass Boiler.

The Energy Barn at Rookery Farm

This is such a great step forward in producing a sustainable energy source and is very much in keeping with the ethos of both our agriculture and accommodation businesses.

Why biomass fuel?

People ask why we have gone down this route, and there are some very simple facts about Biomass energy that gives the whole initiative viability.

The first is the cost effectiveness: it has been proven that wood-fuelled heating systems – in our case wood chips – can save a great deal compared to our former conventional oil-fired boilers.

It is also a low carbon option. The carbon dioxide emitted when wood is burned is the same amount that was absorbed over the months and years that the plant was growing. The process is sustainable as long as new plants continue to grow in place of those used for fuel. There are some carbon emissions caused by the cultivation, manufacture and transportation of the fuel, but as long as the fuel is sourced locally, these are much lower than the emissions from fossil fuels.

The third major factor is our desire to use a sustainable energy source. We all know the debates raging about climate change, and the undeniable fact that fossil fuels are fast running out, so we wanted to do our bit to ensure an energy supply in the future.

What is biomass fuel?

Biomass fuel can be sourced from a “closed carbon cycle” system, where the amount of carbon emitted during the burning of fuel is balanced by the planting of trees. This is an environmentally friendly way of harvesting fuel to provide heating. It therefore cancels out the harmful effects of carbon being released into our atmosphere. Trees need carbon dioxide to grow, making this a symbiotic partnership and one which is environmentally friendly.

The term biomass refers to a type of fuel sourced from living/non living plant matter, which, besides wood chips, can be derived from either wooden logs or wood pellets.

Wood chips stored in the Energy Barn to ensure a constant supply of hot water.

The technical aspects of our Biomass Boiler

Our Biomass Boiler is German 200kW Maximum Output HDG Bavaria Biomass Boiler and it comes matched with a 6,000 litre buffer tank. It is a relatively simple piece of machinery – it runs on wood chip, which is delivered in 20 tonne batches on a walking floor artic lorry. It has a fully automatic feed with automatic de-ash system

You can see our “Energy Barn” which houses the biomass boiler and fuel store behind Rookery Farm. By necessity it is housed in a large building, a 12 metres by 18 metres, purpose-built steel portal building.

The hot water stored in the buffer tank circulates through the district heat main to the seven properties. Plate heat exchangers and hot water cylinders transfer the heat and hot water to the properties respectively.

How does the boiler work?

A biomass boiler works in a very similar way to conventional boilers, combusting fuel on demand to produce heat that is then used to heat water. Biomass boilers together with their fuel stores are normally substantially bigger than their fossil fuel-burning brothers though, for a number of reasons.

Since they are burning wood chips as opposed to, in our case oil, the fuel store needs to be larger to hold the larger volume of fuel. The automatic feed requires additional room and we also keep a supply of wood chips handy so the hot water supply is always maintained.

And for any guests concerned that the boiler might ‘pack up’ (a very unlikely occurrence) we have a contingency plan. Backup heating is provided from two of the old oil fired boilers from the houses plumbed into the buffer tank while backup hot water supply is via immersion heaters in each of the houses’ hot water cylinders.