Sustainability
Why is it all about Science and Maths in sustainable living?
Both of us worked as Research Scientists. Gaby the Botanist, Biochemist and Immunologist and myself a Physicists, Engineer and Mathematician. Everything on this world is governed by Science and Maths. If you look at rivers meandering through the land, the number Pi comes to mind; working out the materials and design for the hay barn or installing a rainwater harvesting system calls for STEM (Science, Technology, Engineering and Maths) is calling. An excellent place to find even more ideas about intelligent and environmentally sustainable technology is the Centre of Alternative Technology in Wales.
Gaby’s skills are essential for growing vegetables and fruit, managing the grassland and meadow and the livestock. Whether it is vaccinating sheep, giving vitamin D boosters to the alpacas or ensuring that the hens are mite-free. Gaby always knows the answer.
Is it just us?
No, not at all! There are many other locals, some of whom have even banded together. A personal favourite group is “Milborne Port Climate and Nature Action” as they regularly post very interesting articles, which you can see here
Ground source Heat Pump – Replacing the oil boiler
In 2018 we made a major step towards sustainability and carbon-neutral living by investing heavily to replace our oil heating system with a ground source heat pump.
We have now been fossil fuel free for almost six years. We have taken out our oil burner and installed a ground source heat pump. This means no more exhaust or heating oil fumes. No more more fossil fuel is transported to us or extracted through sea or land drilling polluting nature.
This is a significant step towards sustainable living.
We have been harvesting our rainwater for the last nine years. We use it to water our fruit and vegetables, supply our bath, and as drinking water for our geese, ducks, Shetland sheep, alpacas and hens. In the process it saves lots of costly treated tap water in the process! Our laundry is also washed with beautiful soft rainwater, saving a significant amount of washing liquid.
How does a heat pump work?
The schematic below shows the principle of a ground source heat pump (GSHP). On the left-hand side of the diagram is the harvesting of the earth’s heat energy, the centre part is the heat pump and the right-hand side are the heating elements, either underfloor or radiator heating. A heat pump works in principle like a fridge. Instead of extracting heat energy from food and drinks, the heat energy stored in the soil is used. This is provided by the sun heating the soil and rainwater carrying warmth down.
The essential outside work to harvest the earth’s heat energy
These photos show you the outside work, i.e. the left-hand side of the diagram. We dug 500 metre long trenches for the plastic tubing. That tubing contains water with anti-freeze liquid to harvest the earth’s heat energy.
A trench digger scraped out the soil up to a depth of 1.2 metres. This was a very slow process, about one metre per 10 minutes. With a total length of 500 metres the digger spent quite some time on the field munching its way through the clay.
We dug and laid two loops returning from the field allowing 2000 litre per hour to flow. This is more than half a litre per second and almost one pint per second, flowing to and from the heat pump.
One of the photos shows the turning point of the loop and a little bit of the necessary earth movement, with a Mechanical Engineer for scale.
Outside plumbing of the ground source heat pump
The final arrangement outside looks like this. In the photo, you can see an expansion vessel, ball valves and a pressure gauge. This is to monitor the pressure of the outside pipes. Our system works at one bar which is very similar to the average atmospheric pressure.
The heat pump is environmentally friendly and sustainable. Additionally, it provides a lovely warm house with warm water always available.
My first academic research project
Funnily enough, I wrote my first Bachelor’s thesis in Engineering in 1988 investigating a heat pump. Its focus was the heat-exchange performance of an air-heated heat pump. Life is like a boomerang, important things return to you eventually, in this case after thirty years. Why is a heat pump sustainable? This is because, for each kWh of electric energy put in, the heat pump generates up to 3.6 kWh of heat energy. So we are generating renewable thermal energy similar to wind turbines or solar cells.
Financing such an expensive project
Everything has a price. Hence, having spent all our savings, we have to find some money to pay for all the bills landing every day on the table. Meaning we need to sell more eggs and honey. I am also sure there are more learners who need private tuition in Physics, Science, Maths and German. There is nothing more rewarding than seeing the light bulb effect in my tutees. So come on people – the GCSE exams are lurking on the horizon. There is only one shot at those.
If you are interested in the concept of a heat pump please come and see us.
Why is a flowery garden so important?
To be happy and healthy we need to use and stimulate all our senses. We see the beautiful colours of flowers, listen to buzzing bees pollinating them, and smell the scent. All of this influences our mind to become open to new ideas, constantly growing to start new projects to improve our environment and live sustainably. We are interdependent with nature. If we use our energy to help nature we will get in return a garden of joy good for our soul and body. What a pretty delphinium! Beautiful roses with a lovely scent. The very tall flowers of our Yucca.
What’s next?
Photo Voltaic (PV) cells or a Wind Turbine
This will be the next step to generate our own electric energy. We need to do a bit more research and get some quotes before we decide.
WET – Wetland Ecosystem Treatment
We also thinking to increase our biodiversity by installing a WET (wetland ecosystem treatment) system producing a grass crop with a large pond offering a wetland habitat for all sorts of organisms and wildlife. We visited Monkton Wyld Court and they showed us kindly their WET system installed by Biologic Design Ltd in Herefordshire. Absolutely brilliant, one is using its own sewage to produce a crop and feeding a pond which altogether creates a natural wetland habitat.