The consultation document proposes a three-stage hierarchy for designers to achieve zero-carbon. The first step for energy efficiency requires compliance with Part L of the Building Regulations. This stage may also encompass other regulatory instruments, such as a mandatory requirement to design to Level 6 of the Code for Sustainable Homes (see Greeen gloss code? article).
The second stage proposed by Government is something called 'Carbon Compliance', which essentially is the use of on-site micro-energy generation. A report by the UK GBC Zero Carbon Definition Task Group believe over 80 per cent of homes in the UK to be unable to achieve zero carbon targets this way. The development of near-site and off-site low and zero-carbon energy generation is also being proposed.
Initially there were reservations over whether the use of biomass technologies could be included in the zero carbon strategy. However, the government appears to be in full support of using biomass systems both within new homes and as a source of direct heat from nearby off-site generation.
The third stage in the zero-carbon strategy is what is known as 'allowable solutions', which is a buy-out fund or form of carbon offsetting through high quality international investment in low and zero carbon projects.
This third way will, it is believed, only be permitted where energy efficiency and carbon compliance are unable to be achieved totally through on-site and near-site measures achieve the goal of zero carbon - in other words the residual emissions.
The government is proposing a system of credits to permit off-setting to occur. Credits will be awarded to developments that have a range of energy-saving criteria. For example, energy-saving appliances and low and zero-carbon technology capable of exporting energy to the grid will earn credits to enable an offset of residual carbon emissions.
The government would prefer off-site low and zero carbon technologies to be included in this part of the hierarchy by feeding into the national grid.
So will the policy work? The first two parts of the hierarchy - energy efficiency and carbon compliance - are signs of forward thinking. With a few tweaks, off-site low and zero carbon energy generation could play an integral part of reaching the zero carbon target, but only if the contribution from the grid can be guaranteed to be clean.
Other questions remain to be answered. For example, with allowable solutions, will off-setting contribute to reducing carbon dioxide emissions enough for claims of zero carbon to stack up - not just initally but over a sustained period? Or is it, as some might argue, just a way of covering up holes in the system, and easing collective guilt?
Off-site low and zero carbon energy generation technologies sounds like reasonable measures, but if they are supplying to the grid as opposed to supplying directly to a development, what guarantees will there be that this clean energy will not be lost in the overall electricity generation? This is a key issue, especially when it's mixed with the output from the proposed eight new coal power stations (each potentially generating eight million tonnes of CO2 per year) that the Government is keen to build.
These questions highlight the credibility gaps that still exist between intention and delivery in Government's push for a low carbon and sustainable energy future. Whatever transpires following the zero-carbon consultation, tackling the issue effectively will not only significantly affect the environment, but also our pockets.