Wednesday, 29 September 2010

The basics revisited

I've had so many people asking me for advice on saving energy, reducing emissions and consuming less in recent weeks. I do love advising people on these topics but, really, I'm delighted because it shows that many more people are becoming interested in reducing their own impact.

So here's my attempt to summarise the things that we can do to reduce our emissions from energy use at home.

I won't be able to get everything in but feel free to let me know anything important that I've missed. Other guides to the basics are available, such as this one from Tesco, but I'd recommend caution with any advice - for instance, Tesco claim that DAB digital radios save energy compared with your existing, analogue radio - the truth is precisely opposite.

Before you even start thinking about cutting your home energy use, please please PLEASE begin recording your meter readings on a regular basis! Monthly is ideal. Weekly if you're really into it, like me, or if you want to use i-measure to compare your energy and emissions with other, similar households.

If you can put your readings straight into a spreadsheet then you are well on the way to seeing exactly what benefit your energy-saving efforts are giving you. If not, just write them down in a small book or log-sheet and keep it in your meter cupboard. When you want to know how much you have saved, you'll have the all-important data to answer this question.

Our homes are responsible for over a quarter of Britain's carbon emissions while, altogether, buildings account for more than half our emissions. What works at home may well be applicable at work, in the shops or in public buildings across the country.

The biggest chunk of our home energy use in Britain goes on heating: both air (space) and water. Ultimately, this heat is all lost to the home's surroundings. Energy efficient heating involves slowing the rate at which our heat escapes, so that we can maintain a comfortable indoor temperature using less fuel and therefore less emissions.

The cheap and easy place to insulate in most houses, or top-floor flats, is your loft. I've posted lots of links to various types of loft insulation in this blog but, basically, any DIY store should have plenty of top-up insulation available at half price, or BOGOF, subsidised by the energy companies under their carbon reduction commitment. The recommended depth of loft insulation is now 275mm (call it a foot) but I've gone for 400mm over most of my loft, to make up for the storage areas where I have only got 200mm of rigid urethane foam. This works, in conjunction with reflective bubble-wrap on the rafters, to keep my water tank from freezing in winter.

Post-war houses typically have cavity walls and these need to be insulated. If yours haven't been done, you will find this an unbeatable investment - it will pay for itself in reduced energy bills in a couple of years! Older houses have solid walls, which are tougher to insulate. But all is not lost! If you're redecorating, it's the ideal opportunity to fit high-performance internal wall insulation. Although only 1 or 2 cm thick, these amazing materials can cut heat loss through your walls by as much as 25 cm of mineral wool loft insulation.

Doors and windows are, put simply, holes! To keep your warmth in, fit draught excluders to make sure that they fit securely. This is one of the cheapest DIY energy-saving methods. Nice thick curtains are great insulators and they turn south-facing windows into passive solar heaters, allowing the light and warmth in during the day but preventing it from escaping at night. Just so long as you use them.

Replacement windows and doors are much more expensive than draught excluders and curtains but replacing single-glazed windows and doors with double glazing will make your home warm and quiet and can be a good investment in maintaining the value of your home. The latest energy-efficient windows have cleverly-designed frames to prevent "thermal bridges" - parts of a building structure that conduct heat through the fabric of the building. At lower cost, secondary double glazing can be a fantastic investment and may be the only way to reduce heat loss from windows in listed buildings or conservation areas. Magneglaze polycarbonate panels fit inside your existing window-frames and are secured with magnetic strips. They cost £100-120 per square metre. They will reduce your energy bills and emissions, cut down external noise and reduce condensation. Of course, you could make your own secondary glazing - we used the ultimate cheap solution in our previous house, until we could afford to fit decent double glazing.

Other holes are responsible for heat loss as well. Chimneys, kitchen extractors, cat flaps, gaps round pipes and even air bricks. Ventilation is important but modern buildings, built to 'passivhaus' or even zero-carbon standards, are designed to be hermetically sealed. Ventilation is then provided deliberately, using ducted heat-recovery systems that bring fresh air in and pump stale, moist air out without losing its heat. I live right under the Heathrow flightpath and fitted one of these systems to my 1950s house in 2008. We have benefited in 3 ways: firstly, the energy savings from heat recovery and an airtight home (I have found and blocked up all the holes in our walls and around doors, windows and pipes). Second, clean, filtered air means less dust and smells in the house (and you should see the inlet filters when I change them every quarter). Finally, the ventilation system means that we can keep our windows closed at night and this means that we are not woken up by aeroplanes before dawn!

The last place to consider heat loss is through the floor but, as I am not prepared to raise the level of my home's floors, there is very little that I can do to cut this heat loss.

While space heating is very seasonal, we need hot water all year round. Solar water heating is a big investment (about the same as a new boiler) but it does enable you to shut down your boiler in the summer months. If you have a hot water cylinder, it pays to insulate it thoroughly - it should keep your water hot for 24 hours.

You can also save energy, and cut your emissions, by using less hot water when you shower. First, get used to turning off the shower water when you lather up. This technique is called a navy shower, and allows you to have a relaxing and effective shower while using running water for just 2 minutes in total. Second, fit a low-flow device such as this one from EAGA, available free in a government-funded energy-saving scheme.

Use your heating controls. Make sure that the hot water cylinder is fitted with a thermostat and that you set it to a lowish temperature, that is hot enough for showers / baths / washing up.
Lots of people prefer to keep their hot water "always on" which means that your heat loss from the cylinder is continuously at its worst. Instead, limit the time that the boiler runs - for both hot water and for central heating - because heating fuel consumption is, surprisingly, well correlated with running hours! It's also worthwhile replacing your room thermostat (the temperature dial) with a modern, "adaptive" thermostat. In my home, this saved 10% on the winter gas bill because it learns how your home responds to the boiler and prevents the room temperature from over-shooting and wasting fuel. Lastly, thermostatic radiator valves (TRVs) can help to reduce heating bills by limiting the temperature in bedrooms or unused rooms. They can only do this if you adjust them to meet your needs. Don't have a TRV on the radiator nearest to your room thermostat - it will prevent the room 'stat from turning the boiler off when it should.

Many of my earlier entries in this blog detail how to replace inefficient lights with energy saving alternatives. The variety is bewildering so I would just say here, make a start. Don't try and do it all at once. Pick on a type of lighting in your home and try one or two replacements. When you find the energy-efficient lighting solution that you like for that type of bulb, fit it to all instances of that light in your home. When you're ready for another round, pick on another type, and so on. I started in 2006, with the SBC (small bayonet) golfball bulbs that were all around my living and dining rooms. I moved on to ceiling mounted BC (bayonet) and ES (screw) bulbs and then tackled the mains halogen bulbs called GU10s.

Next came the fluorescent striplights over the kitchen counter and the filament striplights found in our drinks cabinet and lots of bathroom lights. Replacing these with LEDs was a big win, reducing power consumption of those lights by 90%.

Lastly, the plethora of low-voltage halogen lamps that have colonised our homes in the last 10 or 20 years. It is now becoming practical to replace these with LED bulbs but to obtain equivalent brightness to the commonest halogen lamps (50 watt) remains very pricey.

After heating and lighting, our gadgets are the biggest energy consumers in our homes. Top of the league are WET appliances - washing machine, tumble drier and dishwasher. Minimise energy wastage by running them less often, waiting until they are fully loaded, and selecting a lower temperature. Your kettle also swallows up a surprising amount of energy for such a little feller - be sure to boil only as much water as you need.

Next comes COLD appliances - fridges and freezers. Any of these over 10 or 15 years old are likely to be costing you a fortune to run. My 1990 Zanussi larder fridge got through almost 800 units of electricity (kilowatt-hours or kWh) a year: its same-sized replacement runs on just 80 kWh a year! At a cost of less than £200, this new fridge has paid for itself within 3 years.

Thirdly, entertainment and IT are using an increasing proportion of our household electricity. The proliferation of little black plugs and in-line boxes shows how many transformers we have plugged into our sockets in recent years. They ALL need to be switched off at the wall when not in use because they all (apart from the very latest, super-green phone chargers) suck power from the grid 24/7, regardless of whether or not we are using them. Remote controls like Bye Bye Standby are great for lights and home entertainments but, for all the black boxes you have around the home, the best thing to do is to hunt them down and UNPLUG them. Just plug them in when you need them and pull them out when you're done. No cost and even a bit of aerobic exercise for free!

Specifically on IT, I am writing this blog on my Fit-PC 2. This magical machine (technical term, net-top) is a small block of aluminium, about the size of two fag packets side-by-side (I don't smoke but it's the best illustration), that runs Windows just as well as my old tower PC but consumes less than 10 watts! When I got it, I expected that it would only be good for email and spreadsheets but I've come to rely on it for all my digital photos, music (I run a Squeezebox sever on it the whole time), Skype, YouTube and even BBC iPlayer! It's not quite as quick as my old PC when it comes to playing DVDs but, to be honest, I don't want to do that on my PC.

Another brilliant gadget for power saving with your computer bits is called the Intellipanel. You plug your computer and all its peripherals into the panel and, when you shut down or hibernate your computer, it kills the power to all the peripherals. It has special sockets for external hard drives, so that these don't crash if they're still running when the PC stops. You can even switch the Intellipanel off at the wall when everything's off and, when you turn it back on, it is ready to detect when you press the power button on your PC for another online session. Magic!

This post has concentrated on reducing home energy use. In my next post, I will review other aspects of sustainability in everyday life in modern Britain, such as food, recycling and travel.

Thanks for reading and don't hesitate to get in touch: either leave a comment or email cutyourcarbon (at) gmail (dot) com - this is not a clickable link because I don't want lots of spam from automated crawler bots.