The Cost of the Move to Biomass

There is an article in this weeks Economist which looks at the potential downside of the EU’s move toward Biomass as a means to reach its target of generating 20% of its power by renewable energy.

EU planners want 1210 Terawatt hours (TWh) of energy to come from biomass by 2020 (compared to 500 TWh from wind power). The majority of that biomass will be used to heat things – primarily in domestic wood burning stoves and boilers in Eastern Europe, but there will still be more electricity generated by burning the remaining 20% of the biomass than from all solar and offshore wind turbine generation.

While some of the biomass will come from crop residues and other waste products, the majority will be from wood – trees from sustainable forestry.

Biomass for electricity generation

While this is seen as being carbon neutral – plant a tree, it absorbs carbon, burn that tree, it releases the carbon, plant a new tree, and so on, in reality this is not the whole story. Biomass power stations need fuel, and large power stations need a lot of fuel – far more than can be sourced locally. Therefore huge volumes of biomass material need to be processed (using electricity – probably not renewably generated) and moved hundreds or even thousands of miles from forest to power station (most likely using diesel).

3.3 square kilometres of forest per 1MW of output from a biomass power station, so huge swathes of biodiverse natural ecosystems are likely to be displaced by unnatural plantations with the loss of wildlife habitats and other environmental issues.

Natural woodland ecosystem

The Economist’s argument is that with all these problems, public money should not be spent on biomass subsidies which distort the market, and instead ‘the market’ should be left to choose the cheapest and cleanest renewable technology (and to invest in future renewable technologies) by setting a carbon tax which makes fossil fuels more expensive to use.

Autonomous Robot Solar Panel Cleaner

With huge growth in solar electricity generation in North Africa and the Middle East recently a problem keep recurring – how to keep solar PV panels clean in arid regions with virtually no rainfall and lots of dust. A sandstorm can cover panels with a layer of dust in minutes which will reduce their efficiency by 80-90%.

One way around this problem is to use the some of the solar electricity generated to run a desalination plant to get fresh water to clean the panels, but this is very inefficient and expensive, and requires the solar array to be installed near the sea.

Wall Walker cleaning robot

Miraikikai Inc have an existing commercial product called WallWalker (pictured above) which is an robot wall and window cleaner. It is primarily designed to be used to clean inaccessible windows adhering to them using suction and zig zagging its way up and across them while cleaning.

Miraikikai solar panel cleaning robot

Pictured above is their new prototype automomous solar panel cleaning robot developed in conjunction with researchers at Kagawa University. It weighs in at around 11 kg and has a battery life of two hours.  Its rotating brush cleans the solar panels as it passes over them without using any water.

It is hoped that a commercial version of this prototype will be ready for sale by this time next year (spring 2014) ready to meet demand.

Are Prices of Solar Panels Going to Stop Falling or Even Rise?

The prices of photovoltaic solar panels (PV) have been falling consistently for years, and particularly for the last couple of years. The success of generous feed in tariffs in Germany first and subsequently in the UK amongst other countries greatly increased the demand for PV solar panels, demand which was rapidly met by new Chinese manufacturers.

Suntech solar panels

Thanks to large government subsidies solar panel manufacturing boomed in China with companies such as Yingli and Suntech selling more and more PV panels at lower and lower prices grabbing well over three-quarters of the world solar market. Panel prices are now a quarter what they were in 2007/8. Global manufacturing capacity is now over 60 Gigawatts per year, but demand in 2013 is predicted to be half that at just 25-30 Gigawatts.

Subsidised over-production resulted in panels effectively being sold at a loss and now many of China’s 500+ solar module manufacturers are deep in debt and facing bankruptcy with no sign of a bail out from the government. It is likely that there will be many business closures, consolidation, and reductions in supply in the coming months and years as the market adjusts itself.

At the same time commercialisation of new technologies which offer more efficient solar panels which can be made more efficiently, more cheaply (with future economies of scale) and with less damage to the environment has been delayed because consumers’ demand has been met with the (unsustainably) cheap conventional silicon PV modules.

Even with the latest manufacturing processes, cheap labour, and government subsidies, existing technology solar PV is still more expensive than fossil fuels. Until there is commercialisation of more advanced solar PV technology we will not see PV compete on a level playing field (i.e. without subsidies) and beat fossil fuels on price.

GE thin film photovoltaic solar panels

Therefore although in the short term we can expect solar module prices to level or even rise a little, this will finally open the door to the commercialisation of new technologies currently waiting in the wings (e.g. thin-filmsolar panels) which in the medium/long term will finally give us economically sustainably low-priced fossil fuel beating panels.

Largest Concentrated Solar Power Plant in the World – Shams 1

The world’s largest concentrated solar power plant started operation on Sunday 17th March 2013.  Costing US$600 million to build, Shams I is located in the desert in the west of Abu Dhabi. The 100 Megawatt power plant will supply electricity to more than 20,000 homes in the United Arab Emirates.

solar-power-plant-shams

100MW Solar Power Plant – Shams I

Covering 2.5 square kilometres, Shams I is an array of 768 solar tracking mirrored parabolic troughs which concentrate the sun’s energy onto a pipe running through the troughs through which oil is pumped. This solar heated oil then passes through a heat exchanger generating steam which drives an electricity generating turbine. More than 250,000 mirrors were used in the construction of the parabolic solar collectors.

solar-concentrators-shams

Shams I – 768 tracking parabolic solar concentrators

Shams I has a dry-cooling system which greatly reduces the amount of water this power plant will use – a vital feature considering its arid desert location. Dry-cooling uses the air to condense exhaust vapour from the steam turbine instead of water. Water cooling is cheaper where possible/practical, but the best geographical locations for solar generation unfortunately tend to be very dry places. It is approximately 5% more expensive to build a concentrated solar power plant with dry-cooling, and the electricity generated will be 10% more expensive than from a water cooled power plant.

At US$600,000,000 for 100,000,000 Watts of installed power, it sounds quite expensive – US$6 per Watt, but perhaps it was all of the associated infrastructure which added to the cost rather than the choice of solar concentrator technology over simple solar photovoltaic technology.

Comparing the costs of this solar concentrating power plant with solar photovoltaic power plants of equivalent size, the Rovigo PV Power Plant in NE Italy cost 276 million Euro for 72MW of installed PV capacity when it was built in 2010 becoming briefly the World’s largest PV power plant (US$5 per Watt), but since then the much larger 145MW Neuhardenberg Solar Park in Germany was constructed for US$365 million, or just US$2.50 per Watt.