Zero carbon goal needs firm foundation
Imtiaz Farookhi, BBC The Green Room 25 Feb 08;
There is no "magic bullet" solution when it comes to meeting the UK government's ambitious target of making new homes "zero-carbon" by 2016, says Imtiaz Farookhi. In this week's Green Room, he argues that poor use of technology will be just as bad as doing nothing at all.
The UK house building industry faces a serious challenge.
With about 27% of the nation's energy used in homes, the sector has turned to cutting-edge innovations to meet government targets for all new homes to be zero carbon by 2016.
The target is clearly ambitious, but there is no "magic bullet" solution when it comes to domestic renewable energy.
Therefore, our message is one of caution; the last thing we can afford to do is create homes that are not fit for purpose.
The successful implementation of microgeneration and renewable energy technologies is vital if we are to ensure that the work of the housing industry matches the government's aspirations.
Obviously, communities and homes of the future that we design and build today must deliver on the environmental promise to reduce carbon emissions.
But we must ensure that consumers of the future do not suffer from short-sighted decisions and the failure to use technology in the right place and for the right reasons.
We cannot risk a situation where one, two, or three generations of consumers will have to live with the legacy of poor decisions made today.
The NHBC Foundation is committed to ensuring that the industry has the tools it needs and the research data it requires to be able to make sound, well thought-out decisions which meet the aspirations of both homeowners and the government.
Tools for the job
The purpose of our new report, A Review of Microgeneration and Renewable Energy Technologies, is to ensure that builders and developers understand that not all options that are currently available will be suited for every development.
Our research has made it clear that much more thought and planning is required in order to gain the maximum benefits from the technologies that, although currently in their infancy, are likely to be incorporated into future zero-carbon homes.
The report evaluates eleven types that can help us cut carbon emissions on the domestic front.
These are: biomass, solar photovoltaic, solar hot water, wind power, ground source heating pumps, air source heating pumps, absorption heat pumps, small-scale hydroelectric, micro-combined heat-and-power, renewable combined heat-and-power and fuel cells.
In order to understand the effectiveness of the various technologies, it is necessary to evaluate issues such as payback periods, seasonal variation, location, as well as local planning requirements.
Our findings showed that whilst renewable energy can provide a cost-effective supply in many circumstances, it needs to be understood that the performance of a particular system will be very dependent on local conditions.
For example, too much shade on a solar system will limit the potential output, in the same way that lower average wind speeds could reduce a turbine's efficiency.
Biomass boilers are a good example of a system which offers strong potential for carbon savings. Using wood fuel in the domestic sector holds the promise of being a truly renewable energy - provided the fuel comes from sustainable sources.
Biomass systems can have high levels of efficiency, typically 60%-80% in ranges, pellet stoves, log stoves and log boilers.
But they require careful installation, maintenance, and also require a sufficient amount of space to store the fuel which generally has to be bought in bulk.
In areas that are designated as smokeless zones, some systems will not be suitable, although modern systems generate considerably less smoke than their older counterparts.
Went the wind blows
Wind power is often seen as a panacea for renewable energy delivery. However, in the domestic sector, these systems may generate more carbon than they save when the turbines' manufacture and delivery is taken into account.
They require uniform wind speeds of 5m/s or more in order to work efficiently, but obstructions such as trees and other buildings can have a significant impact on this.
In addition, wind energy is not uniform across the country so these systems are not suitable for every region.
This means that a site-by-site assessment must be undertaken to discover where their use will gain maximum benefits.
The fact that there is no one-size-fits-all solution is further demonstrated by small-scale hydroelectricity.
Relying on a constant flow of water to generate electricity, the power outputs of these systems will vary seasonally with flow rates.
Also, the cost of installation may be prohibitive when set against the amount of power these generate in certain circumstances.
The capability to generate electricity is increased by the size of the vertical distance the water falls, known as the "head". Greater heads tend to generate more electricity.
Planning issues are significant because it is not always possible to obtain permission.
Testing times
The challenge presented to the housing industry is clear. We are facing some of the toughest tests seen for decades, given these zero-carbon and housing-growth targets that have been set by government.
NHBC has been working closely with government and industry to ensure that the needs of customers are taken into account in the drive to zero-carbon housing.
We welcome the opportunity to work with the new Housing Minister, Caroline Flint, because failing to plan and appropriately implement new measures will be just as bad as doing nothing at all.
We must work hard to deliver on the zero-carbon agenda but without ignoring the realities and issues surrounding the various technologies on offer.
The industry needs time to plan and to manage the implementation of the ambitious 2016 target to ensure that there is a cohesive approach.
It is important that the sector is allowed to make informed choices, based on sound science and safe technologies, backed up by effective testing and accreditation systems.
Imtiaz Farookhi is chief executive of the UK National House Building Council (NHBC)
The Green Room is a series of opinion articles on environmental topics running weekly on the BBC News website
