Fresh planning rules are about to be introduced that call for developments to generate 10% of the energy they will use from on-site renewable sources. We ask whether this is an entirely serious suggestion …

Cities with propellers on
Credit: EMPICS Sports Photo Agency

We have entered the renewable energy age. In the space of just a few years, windfarms have sprung up across the remoter parts of the UK – out of sight and out of mind for most people. But new planning guidance promises to thrust the renewables issue right under the noses of developers and the construction industry and is guaranteed to stir up as much controversy as the siting of wind farms in Cotswold beauty spots.

The new guidance is called Planning Policy Statement 22: Renewable Energy. It allows local planners to demand that renewable energy plants be built into new developments. It is prescriptive, too. Solar and wind energy, borehole cooling and combined heat and power plants fuelled by biomass are acceptable, but other technologies – such as CHP plants powered by fossil fuels – are not. Some pioneering local authorities are already demanding renewables as part of schemes and a contribution of 10% is becoming the de facto figure. These include the London boroughs of Merton and Croydon, and London mayor Ken Livingstone expects the same figure for all developments that are referred to the GLA for approval. Meanwhile, swaths of local authorities elsewhere in Britain are intending to follow suit.

All of this begs the question: is the renewable energy drive a worthy aspiration or just a touch naive? Robert Cook, a research engineer at consultant Buro Happold neatly sums up the argument. “Renewable energy is something we should try and use,” he says. “But we should only be using it where it’s appropriate. With some projects, it’s appropriate to produce 50% of energy needs using on-site renewables, but in other cases none. The problem with 10% across the board is that it’s inflexible.”

He says the case for on-site renewables is largely determined by location – rural sites often have plenty of room for solar panels and there are less people around to object to wind turbines. The problems start with urban sites where there is very little space. “We were asked to provide 10% of the energy needs for a development from renewables,” says Peter Rogers, director of developer Stanhope. “We would have needed the whole site plus some extra to generate the power, so I am very sceptical about this.”

Getting buildings to use less energy in the first place has to be the first step forward. Producing 10% of a gas-guzzling building’s energy using renewables is worse than building an energy-efficient building without any renewables at all (see Stratford City, overleaf). “Reducing the energy consumption of the building is cheaper than producing the energy from renewables,” says Rupert Blackstone, a senior engineer specialising in energy at Arup. “And, of course, if you reduce the energy consumption of the building, then its energy footprint will be smaller, making it easier to meet the 10% target.”

If this requirement is a starting point for negotiating a more energy-efficient building then it could be workable,” says Crispin Matson, director of services engineer Rybka. “I think if they stick rigidly to 10% renewables as a matter of course, irrespective of how energy-efficient the building is, then it’s a flawed policy.”

Reducing the energy consumption of buildings is cheaper than producing it from renewables

Rupert Blackstone, Arup

Once buildings are energy efficient then, and only then, does using renewable energy become sensible. But is it realistic to produce that renewable energy locally? Terry Brown, a partner at GMW Architects, says: “I’m a great supporter of renewable energy on the national level, but not on the local. For example, big wind turbines are more efficient than small ones.” Rogers is equally cautious when it comes to efficiency. “You can go with biomass but if you are in the middle of London, by the time you’ve trucked it in you’ve probably used more fuel transporting it than is in the material,” he says.

Rogers believes a localised approach makes no sense. “You need to think strategically – for example, should we be laying a network of hydrogen pipelines? For me, that’s more sensible than putting PV panels on a building.”

For example, he believes it is pointless putting photovoltaics on homes, as the occupants are probably out in the daytime when the power is being produced. However, if these panels formed a strategic approach to renewable energy and were connected to the national grid, then it would start to make sense.

Rogers also questions why it has suddenly become the responsibility of developers to produce power. “The generators should be the people who should be doing it – why should developers be energy providers?” he says. “I wouldn’t mind renting out my roof space to an electricity company who would install and maintain PV panels.”

Ultimately the success or failure of the policy will rest with its implementation. Used correctly, it could be a driver for more energy-efficient buildings, but if it is implemented literally it could alienate the industry. “We’ve got to be careful about choosing to be politically correct or driving a future generation of energy-efficient, user-friendly, comfortable buildings,” says Rogers.

Matson also cautions about getting too bogged down in politics. “The whole argument is about reducing CO2 emissions,” he says. “Whether you do this locally or from a windfarm is surely just academic?”

One thing is for certain. This is an argument that will run and run – and we barely even mentioned the money …