Heated debate

Local authorities and the waste industry face plenty of challenges (and opportunities) over the coming years in meeting landfill diversion and recycling targets. I fear what follows is an additional challenge or opportunity! How can we as part of our waste management strategy maximise the contribution that we make to the country's renewable energy supplies?

It is pretty well known that the UK faces an increasing potential long term shortage of energy. Our North Sea production is declining; a number of our nuclear facilities are due to close; and coal has adverse greenhouse gas consequences unless we make carbon capture and storage work - a technology that is only at the demonstration stage. As a result we are increasingly relying on imported gas where we are competing with growing countries in the Far East. The current weakness in the global economy and consequent decline in oil prices will doubtless help in the short term but the long term position is clear.

We are particularly short of renewable energy. Our target in 2005 was five per cent of electricity from renewables, going up one percentage point each year to reach a target of 15 per cent in 2015. Actual renewable production (around five per cent currently) has not been growing at the required rate and is falling further and further behind target. Post 2015 the target gets still tougher with government consulting on how to get to 15 per cent of all forms of energy from renewables in 2020 which implies over 30 per cent of electricity from renewables.{mosimage}

To encourage the development of renewable energy the government introduced the Non Fossil Fuel Obligation (NFFO) in the 1990s replaced by the Renewable Obligation (RO) in 2002. Under the RO, eligible renewable energy gets both the wholesale 'brown' energy price, which non renewable sources achieve, plus the value of the Renewable Obligation Certificates (ROCS). Both are subject to supply/demand but the net result is that the value of the ROC can more than double the price realised by renewable energy, a very major financial incentive.

There is good money to be made by those who bring on new renewable energy facilities.

What not many people know is that waste is currently the largest form of renewable energy in UK, accounting for 30 per cent of renewables or 1.5 per cent of total electricity. It has grown by 600 per cent over the past 10 years. This is from a combination of landfill gas power generation and energy from waste combustion (EFW). More importantly there is huge potential for further growth - the Institution of Civil Engineers estimate that waste could account for the equivalent of up to 17 per cent of total UK electricity.

Waste also has the benefit of providing base load capacity as typical ways of generating energy from waste will operate at full load for at least 80 per cent of the time (compared to only 20/30 per cent on an annual basis for wind). Waste is also a form of 'distributed energy generation' typically located close to the major centres of population or industry. So transmission costs and losses are lower than for certain other forms of renewables. This is not in any sense to decry other forms of renewables - we need every type we can get. However the opportunity to recover energy from waste is altogether much too big to ignore.

Looking forward, EFW will become an increasingly important source of energy as the UK seeks to meet its European Landfill Directive landfill diversion targets. As an example the 'Lakeside' EFW plant under construction at Colnbrook near Heathrow will have an electrical energy capacity of 37MW on waste inputs of around 400 thousand tonnes per annum. Other developing technologies will also play their part in energy generation eg gasification/pyrolysis and, for food waste, anaerobic digestion (AD).

The really big prize however is to find ways of recovering heat as well as electricity from waste. A combined heat and power (CHP) EFW plant can substantially increase the total energy recovery achieved. CHP is a well proven technology widely used in Scandinavia. Waste CHP is a rare animal in the UK, though the recently approved facility at the Ineos site in Runcorn is an example of what can be achieved. The Runcorn plant will have a waste input of around 750 thousand tonnes per annum, and a total energy capacity of around 100MW.

The financial incentives exist. 'Good quality' energy from waste CHP, such as the Runcorn facility, is eligible for ROCS
though the rules are complex. Good quality in this case refers to the thermal efficiency of the plant. At present the ROC incentive is on electrical power only and not on the heat; this has the perverse incentive of encouraging maximum electricity production rather then maximum total
energy from a combination of heat and electricity. A genuine support mechanism for "renewable heat" as well as electricity would greatly simplify matters and this formed part of the Government's recent consultation on the UK's renewable energy strategy (other forms of energy generation from waste such as anaerobic digestion, pyrolysis and gasification, even without heat recovery, are classed as "Advanced Conversion Technology (ACT), It is expected that all forms of ACT will be eligible for double ROCS).

The big issue is finding a use for the heat. The Ineos site has major industrial heat requirements but such sites are not that common in UK. That means we need to find other uses for the heat and here a bit of lateral thinking by councils and waste contractors is required. Uses could include district heating systems for apartments/housing (as in Scandinavia), commercial applications, swimming pools and leisure centres, greenhouses or something else. The normal thought is to try to put waste facilities away from other installations but maybe we have to be thinking of the opposite!

I fear this is yet another thing for councils and waste companies to think about. However the opportunity to make a
significant contribution to UK's renewable energy targets is too big to ignore.