Building the off-grid revolution

SkyShades' Greg Norman


Not being an especially practical person, the prospect of spending the day at a building materials exhibition normally holds all the allure of, well, watching paint dry.

But far from being a dreary convention for construction workers’ accessories, the UK Ecobuild exhibition at London’s Earls Court was more like a gathering of impassioned revolutionaries conspiring to aid and abet off-grid living.

The environmental message has finally got through to the UK building industry -with a vengeance. “I’m here because Ecobuild is now easily the most important trade forum for the UK building industry,” said one senior local authority architect.Yes there were bewildering displays where the emphasis was on ‘build’ rather than ‘eco’. What for instance are the green credentials of stainless steel down-piping or conservatory blinds? A less positive reviewer might suggest that there is still too much green-wash and eco-bullshit in the Building Materials industry.

On the other hand there were literally dozens of kosher companies selling solar and PV devices. Following recent government initiatives around subsidies to micro-generation in the UK, it’s an industry teetering on the edge of explosive growth.

Sadly it is going to be like the wild-west for the next three or four years predicted the director of an international building firm.

“There’s so much consumer demand and so much manufacturing capacity, that you would think that solar will go bonkers within a year.” Trouble is he predicted, solar is going to become a victim of its own success. There will be serious bottlenecks –largely because those manning the barricades of the solar revolution are in truth, dyed-in the wool reactionaries.

“British builders don’t like new ideas very much and they really don’t like acquiring new skills,” he said. “As a result the growth of solar will be constrained in the short term by a lack of skilled installers. Like every other area of building, it will attract cowboys who will be able to charge high prices, but don’t really know what they are doing.”
But the most exciting thing about Ecobuild was the extraordinary range of ingenious new products on offer. Nearly all of them seem calculated to make life off-grid easier in one way or another. Here are some of my favourites.


I nearly walked straight past SKYshades. At first glance they seemed to be selling decorative plastic sheets. On closer inspection it turned out they were indeed selling plastic sheets. But the ‘decoration’ was a thin film carbon-based photo
voltaic cell.

SkyShades is an Australian company boasting golfer Greg Norman as a director. It has only recently launched in the UK. It uses OPV (Organic Photo Voltaic) or Power Plastic sheets produced by US firm Konarka and marries them to SKYShades’ tensioned membrane structures –awnings to you.

Although, the material produces just 35 watts peak per square meter, the company claims it costs just £200 psm fitted. It is flexible, lightweight, versatile, and easy to work with, doesn’t use toxic chemicals in the cells and apparently allows users to avoid building regulations.

This stuff has been available in the US for a couple of years -remember the solar car port and Wal-Mart’s solar ruck sacks. In theory at least the applications are almost infinite and this could be a truly transformative technology.

That’s Builder Scrap, right. Presumably they knew what they were doing when they chose their name. Just get over it. But watch any British building site and stand aghast as valuable surplus materials are dumped because it’s too difficult and expensive to sell them on.

BuilderScrap is a free on-line material exchange where leftover building supplies can be passed on. It reduces skip and landfill costs and of course provides a handy source of cheap or free materials for anyone greening their own homes. www.builderscrap.com

Four years ago Oxford educated engineer Tom Seppings went on a solar plumbing course. He was horrified to see that perfectly sound hot water cylinders were being thrown out simply because they couldn’t marry with the new solar technology.

He spent the next couple of year developing his retrofit heat exchanger which as its name suggests, simply plugs into existing water cylinders. They cost about £200 which is good value compared to the price of a new tank, coil and labour
which could easily come to £700, far more if you have a pressurised water tank.

It’s not going to change the world on its own. But it’s a clever and sensible idea. Anything that reduces the cost of converting to microgen has to be good.

Water is a basic commodity in short supply in many areas. That’s why rainwater harvesting is becoming increasingly common.

A key problem and expense is that rain water has to be collected in big tanks buried quite deep. A real drag if you are doing the digging yourself.

The Skeletank is a lightweight tank (35kg) so strongly reinforced that you can bury it in relatively shallow depths of less than half a meter. Better still it can be installed by someone with average DIY skills. Money saved, water harvested,
job done.  https://skeletank.com/

Sempatap Thermal
As much as 50% of domestic heat can be lost through solid walls. The answer is of course solid wall insulation. Some people use thick cork –but an extra nine inch layer on the outside of your home can look a bit, well, odd. Others use newer insulating materials –but they can cost £80 a meter installed. That could be thousands of pounds on even a moderate sized house.

Sempatap Thermal is just insulation on a roll. What a great idea.  It’s as easy to apply as wallpaper and according to its manufacturers it shows “considerable energy and cost savings.” (It would be nice if they could be more specific). It can
be decorated with virtually anything –paint, wallpaper, even tiles. And it and has a life expectancy of 30 years. https://www.mgcltd.co.uk/Products/Thermal_and_Acoustic_Insulation/SEMPATAP_THERMAL/

The best I’ve saved for last. Clayworks sells unfired clay blocks, plain clay plasters and pigmented clay plasters. It is also a contractor for ‘cob’ building -a traditional construction method using hand-made mud loaves or ‘cobs’, made from clay, sand straw and water.

It’s as low tech as you can possibly get. Stone Age man would have been comfortable with this technology. But it makes for beautiful cheap, low-carbon  buildings. Building just doesn’t get any more ‘eco’ than this.

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