Hever Castle is committed to becoming more environmentally friendly and efficient and is continuing the process of replacing old equipment with more energy efficient solutions.
We replaced our 650KW woodchip boiler with a 995KW boiler in November 2013. This new, larger boiler has allowed us to add several more houses, the toilet blocks and the forthcoming military museum and classroom. It also means we qualify for something called the Renewable Heat Incentive which is a Government scheme encouraging more renewable sources of heat to reduce fossil fuel burn. The Castle’s hand was slightly forced on this as, if we had not changed our boiler, we would not have qualified for this grant and because of the success of the grant and so many more people putting in biomass boilers, the danger would have been that, as timber prices increased, we would have been priced out of the market. However, we did want to add more properties onto our biomass boiler network and clearly it is much better to burn locally-sourced timber than use mains electricity or LPG or oil, as we have done in the past.
The biomass has been a huge success with the total cost of heating the entire site on the previous 650KW boiler up to the end of November 2013 approximately £30,000 net. The local residents on the system currently pay the Castle for the heat they use at a price slightly below the typical oil price. For householders this is very efficient as they are only paying for the heat and not for the running of a boiler. In normal circumstances the boiler would have a certain amount of loss as it generates the heat. Of course the Castle gets some loss through the pipes, but it is very small. However, despite the pipes being hugely insulated and not surprisingly quite expensive, one consequence is that in cold weather we get the odd line where the snow melts first. This is merely because there is a constant, albeit low release of heat all year round as the hot water is pumped round the ring main round the estate. It is also worth noting that in 2009 the cost of heating the castle with oil and LPG came in at over £100,000 when oil was 38p per litre. That same gas oil has been as high at 80p since then, although currently it is typically over 60p per litre now.
The vast majority of the timber we use comes from local woodlands in Kent, Sussex and Surrey and at the moment only a small percentage is taken from our own woods. We mostly burn chestnut coppice, which is slightly cheaper than most other firewood because of the fact that it spits in an open fire. However it has a high calorific value and it means that ultimately we help support old chestnut coppice woodland, which is usually very good for wildlife. Some of the chestnut coppice woodlands in this part of the country are many hundreds of years old and they are typically very good for bluebells. It is particularly satisfying that, whereas in the past we were buying oil that came from all over the world, usually lining the pockets of large multi-national companies and wealthy sheikhs, we now pay local landowners, foresters and hauliers, keeping the money local and helping to ensure the continual maintenance of local woodlands.
The other particular benefit with chestnut is that, because it is coppiced, there is no need to replant after felling, as the new timbers grow out of the stump of the old. It also means that some of the stumps are very old indeed and of course they continue to grow underground, locking in lots of carbon permanently.
Not quite such an attractive subject, but we renovated the sewage treatment here at Hever Castle approximately seven years ago and this has proved to be particularly beneficial for wildlife, as well as proving significantly more reliable in that it does not really break down. William Waldorf Astor installed the most amazingly sophisticated sewage system in his day, which involved collecting the sewage underneath the castle and injecting it by air across to the stable blocks on the other side of the public road and from there back underneath the road and then underneath the river and one mile up to the golf course. It then flows underground across the golf course before entering our sewage lagoons.
In the first lagoon, the liquid is not particularly attractive. However it does not smell as much as most people would expect it to. The prevailing smell is that of ammonia, but the plants growing around it, which have been specially selected for their love of this liquid, have grown exceedingly well and you will now see tall stands of reeds, irises, water mint and many other water-loving plants. From this initial lagoon, the liquid runs across a special wetland bed constructed of different grades of gravel on a gentle slope, inter-planted with literally hundreds of plants. Indeed across the whole lagoon site we have planted 20,000 plants.
From this ‘washing bed’, the sewage, which is now crystal clear, runs through another smaller washing bed into its first clear lagoon, also surrounded in reeds and then travels down a large gravel slope, again with lots of plants growing on it, into the biggest lagoon, which is full of all sorts of insects and in the spring is a mecca for the frog and toad. From there it goes into a final washing bed and anything left over goes into a willow copse. The willow trees are now 20-30ft high.
The whole site has become exceedingly popular with wildlife and we regularly hear reed buntings and reed warblers and see a host of other birds, animals and insects, not to mention the many amphibians enjoying this habitat created there.
Literally all of the sewage is gobbled up by the plants and even in the winter, despite the reeds dying back, the reeds continue to grow amongst the gravel trapping all the many nutrients, as well as any pathogens. Plants are particularly good at gobbling up and killing pathogens, which is why these systems are so successful. It also does not rely on any electricity and the only maintenance required is a bit of weeding to stop the nettles taking over in places. Once every 10-15 years we will probably have to de-sludge the first lagoon.
Other energy–saving ideas
We are currently investigating the possibility of putting solar power on our greenkeepers’ sheds, which currently do not have mains power and rely on a diesel generator.
One of the ultimate ambitions would be to put a small hydro on the lake. When we previously looked at this a few years ago, the payback on investment would have been over 20 years. However, due to the increasing electricity price, this is starting to look more attractive and I would hope that within five years we will have this electricity generation which could potentially provide us with as much as 15-20% of our electricity requirements.
Meanwhile we continue to replace old fashioned light bulbs with low energy ones; particularly the technology around LEDs has significantly improved and of course the LED lights give off no damaging UV rays for picture lights, albeit they are not cheap.
We will continue to explore ways of becoming ever greener; not only is this good for the environment, but over time it should reduce the bills to keep Hever Castle running. We would rather spend the money on repairs.