Blog: Sustainability

My environmental journey

Ken Munro 28 Sep 2019

I live in an old house near to where I grew up. It had oil fired heating and was unbelievably inefficient and expensive to heat. It was so draughty and cold that we genuinely put my young kids to bed with hats and gloves on. We bought it over a decade ago knowing that the roof needed work, so bit the bullet and had the whole lot off rather than patching it up. That created the opportunity to installed deep Cellotex panels and breathable membranes to improve matters. The old sliding sash windows were also properly draught proofed.

Whilst on the roof helping the roofer, I stuck my head over the chimney and was shocked by the blast of hot air coming up. No, the fire wasn’t on! The draw was sucking warm air out of the house. Whilst a damper or chimney balloon could have helped, given there was already scaffolding in place, I fitted a wood burning stove. Two tree surgeon mates and a couple of local farmers I was friendly with ensured I had a ready source of fairly cheap wood.

That cut our oil bill by nearly half, but I still wanted to do more, given that oil isn’t a great way to heat a house. Mains gas wasn’t an option, so I started looking for other ways.

A ground source heat pump had potential, but needed the radiators to be enlarged and most of the heating system replaced in order to deal with the lower operating temperatures. I wasn’t up for the disruption that would entail. I’m not a great fan of air source heat pumps, given that they are least efficient when one most needs the heat – i.e. in winter!

A friend had recently fitted a wood pellet boiler to replace his oil fired system. This had potential, but after doing some calculations, I would need a significantly larger system. Also whilst pellets were a renewable energy source, they were comparatively expensive and could me rather more expensive than heating oil. There was also some media coverage suggesting that pellets were being imported from overseas.

Finally, I found that log gasification boilers were maturing. Early versions required manual lighting, which was going to be a bit of a faff, but a couple of suppliers had recently launched dual log/pellet boilers that could run on either and auto ignite. It also meant that going on holiday in the winter wasn’t going to result in the house freezing, as the system could auto feed with pellets when one was away.

After talking to various suppliers, I settled on creating a small domestic heat network that fed hot process water to my house, my office and also to my neighbours house. Laying the heat pipes across my driveway made quite a mess, but there was no disruption inside the house, as the feed pipes simply dovetailed straight in to the existing heating system.

So now, my house is heated entirely from burning logs cleanly at around 750C. Almost no smoke & harmful particulates that come from burning wood at lower temperatures.

Only one issue – I go through around 20 tonnes of wood per year. Buying this in pre-cut and dried isn’t financially efficient, so I have a local woodsman deliver me those 20 tonnes in cord wood, from thinning operations in nearby woodlands. My job is to cut those 8 foot cords in to 1 foot lengths and then split & stack them. It takes a while, but I enjoy it in a weird way. Yes, there are some emissions from felling and transporting the wood to me, but the heating oil had to be transported to me too. The wood had to be felled anyway as part of forest thinning operations. I also use a chainsaw to cut the wood to length, but the emissions are a fraction of those from burning heating oil.

The boiler doesn’t connect straight to the heating system – it’s in series with a 3,000 litre thermal store that I heat up during the day, then call down heat from in the evening and overnight in to the morning.

Along the way, I also have solar thermal panels for hot water for the summer months when the log boiler isn’t running.

I’ve had electric vehicles since 2015 – first the Mitsubishi Outlander PHEV – which only had about 20 odd miles of real range on batteries. It also had some lovely security flaws too. I now have an Audi e-tron as a full EV, which was a bit of a leap of faith early on, but has come in to its own as the public charging network has grown in the last year or so.

There’s more to be done though: next is a solar PV array with a Tesla Powerwall or similar, so that I can increasingly charge the car from electricity I generate myself. I’m hoping that in summer I can export power back to the grid too.

Finally, my wife and kids are mostly vegetarian now, so I’ve followed suit. Yes, I still eat meat, but well under half of the amount I used to.

The big issue with all of the above is that many ‘green’ technologies can be expensive. Everything that I’ve done has already paid back its capital costs and I’m now seeing the benefits of much cheaper heating, but the up front costs could have been prohibitive. I should add that I don’t get feed in tariffs for the log boiler, though could have done had I fitted it a bit earlier.