Code for Unsustainable Homes

Posted on August 14, 2010 by Doug King

I’ve been looking at options for sustainable housing recently following a raft of competitions for housing associations who want to achieve Level 5 of the Code for Sustainable Homes. Level 5 requires zero carbon emissions from heating lighting and ventilation, so you have 2 options; install a conventional boiler and enough extra PV to offset the carbon or install a biofuel boiler. Since PV is vastly expensive, this really only leaves the biofuel boiler.

Now, we can design well insulated housing these days with peak heating loads well below 5kW. However, can you find a fully automatic woodfuel boiler below about 15kW in output? No – at these low loads the only option seems to be manually fuelled room heaters. Wood boilers really need to be fired at full power for a reasonable period to avoid problems with tarring up. In other words the smallest automatic boiler is sufficient for 3-4 homes at CSH Level 5 or 6. This is great if you are a housing association and can install common plant and distribution, but what about developing housing for private sale, or even single properties.

The Government insists that all new housing shall be CSH Level 6 by 2016. So, if you are building a single house and don’t fancy inconvenient manual fuelling, you’d be better off not insulating the house at all in order to create sufficient load for long term reliable operation of your woodfuel boiler After all, the fuel is carbon neutral so you get all the credit even if your consumption is excessive. How stupid is that?

I think that this is another example of legislators adopting a voluntary code and forcing it on the market without ever considering the implications.

No More London Please

Posted on August 10, 2010 by Doug King

Another building that has been getting quite a bit of publicity recently for all the wrong reasons is 7 More London. This new office for PriceWaterhouseCooper is the first building in the capital to be awarded a BREEAM Outstanding rating. Yet when you look at it, this conventional, air-conditioned, steel and glass monstrosity probably should not have even passed Part L of the Building Regulations. Its saviour is that elixir of apparent carbon goodness, biodiesel.

Now is it just me, or is there something fundamentally wrong about an environmental rating system that allows you to construct a building that is just as energy guzzling as all the rest, but then feed its hunger with a scarce and valuable renewable fuel source?

Biodiesel is hardly sustainable, you simply need to look into its impacts on land use and food production to understand that, but it will have a valuable role to play in maintaining essential freight transport in the future. Unless, that is, we consume it all in running un-necessary air-conditioning for poorly designed, inefficient buildings. Actually this is true of all renewable energy sources, we simply cannot generate sufficient to waste it on gratuitous consumption. Oh and by the way I’d love to know how the biodiesel is to be delivered to the building.

The impending energy crisis is likely to be so severe that we will need every drop of fuel available from what-ever source we can find, simply in order to maintain our quality of life. We certainly cannot afford to pretend to be environmentally responsible by rushing to exploit a new resource before anyone else gets there. That’s how we got into so much trouble over fossil fuels.

Kinetic Road Plates

Posted on July 25, 2010 by Doug King

The issue of kinetic road plates came up again today. Doesn’t it sound like a great idea – harvest energy from cars passing over a compressible ramp in the road to drive a generator? Free energy, as long as people keep driving cars.

But hang on – where is this free energy coming from?

Well, since energy cannot be created nor destroyed, it clearly must come from the car’s engine as the only power supply in the vicinity. In order to compress the ramp the vehicle must first drive up it’s incline. The increase in gravitational potential energy created by raising the mass of the car is then converted to kinetic energy as the ramp gently compresses and drops the car back down to road level, driving a generator to create electricity. But, in order to raise the car up the ramp in the first place consumes more fuel, exactly like driving up a hill.

So, rather than harvesting free energy, the kinetic plate is actually stealing a little bit of energy from each car passing over it. That energy must be replaced by burning more fuel; it’s just that the amount of fuel taken from each car is so small that you’d be unlikely to notice.

Now one of the first adopters of this technology is a national supermarket chain – very clever – the supermarket also sells fuel from its own petrol station, so they are onto a double winner. The store gets a free supply of energy from its customers and then sells more energy to the same customers to replace the energy it has stolen from them.

Not enough wind for the Olympics

Posted on June 4, 2010 by Doug King

It is somewhat surprising to read the comment in The Times from Shaun McCarthy, Chair of the Commission for a Sustainable London 2012, that the Olympic Park wind turbine is to be scrapped because there is not enough wind on the site.

The Olympic wind turbine was announced in March 2008 in a blaze of glory. Since then has no-one bothered to check the Government’s Wind Energy Database now maintained by the Department of Energy and Climate Change? This clearly indicates that the location for the Olympic turbine is marginal for economic wind generation.

Generating electricity from the wind is critically dependent on the wind speed which is affected by location. Wind speed is dramatically reduced over cities due to friction with buildings dissipating much of the energy as turbulence. It would be unreasonable to expect the Stratford turbine to generate much more than about half that of an identical machine in open country.

Large wind turbines are a significant investment and if the generation potential of a site is poor then wind energy developers will look elsewhere. This may explain why the ODA has failed to find a new developer prepared to step into the breach after the preferred bidder for the turbine withdrew.

There are few other renewable technologies that can match wind power economically. One must hope therefore that the ODA rigorously enforces energy efficiency standards for the new buildings in order to reduce demand. This would be far preferable to wasting public money on expensive renewable technologies to offset 20% of unnecessarily high demand.

FIT for Purpose?

Posted on March 21, 2010 by Doug King

The Feed in Tariffs have been almost universally welcomed, but has no-one identified any flaws in the system? Well here’s an issue that people aren’t discussing:

Feed in Tariffs are a public subsidy for the rich.

Feed in Tariffs replace a capital grant scheme. Under the previous scheme anyone who wanted to install renewable energy could get help with the upfront cost. That means that people who didn’t have enough money or insufficient borrowing power could get help to install renewables. OK the previous levels of grant were pitiful, but if the money promised to Feed in Tariffs were made available as grants instead many more people could afford to install small scale renewables.

Under the Feed in Tariffs, the Government will instead subsidise energy generated from renewables, but not the cost of installation. This means that only those who can already afford the cost of installing renewable energy can benefit from it. The tariffs have clearly been set at a level to tempt those with spare cash or the ability to borrow, as the returns will be above the interest rate for some time to come. Interesting to note that Spain cancelled their Solar Feed in Tariff after investors nearly bankrupted the system using borrowed money to install solar panels in fields all over the country.

Feed in Tariffs will exclude anyone who wants to install renewables, but does not have the cash or borrowing power. In my opinion Feed in Tariffs should be cancelled and the money used to install free solar water heating for every pensioner household in the country.