About the article: This special Renewable Energy Focus power generation focus previews REMIPEG's latest update, carried out in the first four months of 2012 by Lahmeyer International, and presents an overview for each renewable power sector, based on scenarios up to the end of 2011.

This article is taken from the July/August 2012 issue of Renewable Energy Focus (REFocus) magazine. For a free subscription, click here.

Part one - introduction (click here).

Part two - hydropower falls behind wind and biomass as growth dips

Part three - Wind market still on the up and dominated by China

Part four - 2011 strong year for solar PV despite support subsidies being slashed

Part five - Cost drivers fuel technology switch for concentrated solar

STOP PRESS - SEE ALSO Year in review 2012: Solar PV, by Paula Mints.

Part Six - Bioenergy

Biomass is the most widely used renewable energy source in the global energy system, with a mix of conversion technologies available to create fuel for the production of electricity, heat and transportation. Its use for electricity generation has increased rapidly in the last two years, with key markets being the US, Europe, China and India. In fact, it now ranks third – only behind hydro and wind – as the biggest source of renewable energy used for electricity generation.

Common biomass sources for biofuel production include wood and energy crops. There are four main biofuel categories: solid biofuels, municipal solid waste (only the organic fraction), biogas and liquid biofuels.

In the last decade annual electricity generation from biomass increased about 6%. 2010 was a significant year, with generation up about 15% on 2009. By end 2010, around 62GW of biomass-fueled capacity was installed, generating 249-434TWh of electricity. The biggest share of this (10.4GW) operates in the US, with the next biggest markets being Germany and Brazil.

Assuming a growth rate of around 10% (full figures are not yet available), globally installed capacity is expected to be 68GW by end 2011, with electricity output in the region of 270-480 TWh.

Solid biofuels

About 70% of global electricity generation from biomass is produced using solid biomass in standard electricity-only plants (which accounts for 36% of the market) or more commonly in cogeneration facilities (64% of the market). Generally these solid biofuels are based on wood from forests or turnover plantations, while conversion techniques are based on mature technologies available in a range of capacity sizes.

Solid biomass is used worldwide in industrialised, developing and emerging countries in direct-firing or co-firing with coal or natural gas. In industrialised countries however technologies in use tend to be more innovative, more efficient, and generate lower emissions, largely driven by stricter regulations to manage carbon emissions. With further development or gasification (like the Güssing-concept), solid biomass is expected to be applied more flexibly in the energy sector going forward.

By end 2010, at least 45GW of solid biofuel electricity generation systems were installed worldwide. Assuming annual plant operation in the range of 4000-7000 full load hours, electricity generated was 178-346TWh. For 2011, total installed capacity in this sector is estimated to have increased by at least 2GW, or 5%, to 47GW, with cumulative output rising to 188-329TWh.

The US and Brazil lead the solid biomass generation market, with 10.4GW and 7.8GW of capacity installed by end 2010 respectively. The main feedstocks used in the US are wood and agricultural residues, while in Brazil most of its cogeneration plants use sugarcane bagasse. China and India are other key markets. In 2010, China's installed capacity increased to 4GW from 3.2GW at end 2009, while in India capacity doubled to 3GW.

Significantly, more than 50% (143.2TWh) of the electricity generated from solid biomass is produced in OECD countries. Just under half of that (70TWh) is in the European Union (EU) with the key markets being:

• Germany, with 12TWh (end 2010);
• Finland, with 10.4TWh;
• Sweden, with 8.4TWh; and
• Austria, with 6.7 TWh.

Municipal solid waste

In many countries municipal solid waste (MSW) is used for electricity production in incineration plants. The organic fraction of MSW is often considered as solid biomass and used in thermal waste treatment facilities generating electricity and heat, most notably in Europe, the US and Japan.

In many countries waste management strategies are still in their infancy. Annual market growth rate for the MSW-fuel generation market has averaged around 5% over the last decade, a rate expected to continue in the coming years. In 2010, about 30TWh was generated from organic MSW, with 32TWh expected for 2011.

OECD-countries account for about 90% of the incineration plants operating worldwide. The US heads the MSW generation table, with 9.3TWh produced in 2010, followed by Germany (4.5TWh) and Japan (3.4TWh).

In the EU more electricity from renewable MSW is generated in electricity-only plants (55%). Around 45% is provided by combined heat and power (CHP) plants. In 2010 the total electricity production from MSW was around 17.3TWh. For 2011, annual electricity output is expected to be around 18.3TWh.

Biogas

Biogas can be produced from dumped organic waste during the aftercare of landfills, sewage sludge from waste-water treatment facilities, organic food waste from household and food processing industries, and from agricultural energy crops or manure. Around 27% of the biogas produced in the EU originates from landfills, 10% from sewage sludge fermentation and the remaining 63% from diverse substrates (mainly from agriculture).

Biogas produced via anaerobic digestion can be used in cogeneration/CHP plants or purified to natural gas quality and fed into existing gas pipelines. Electricity generation using CHP plant is a mature technology, recognised as being very efficient for on-site applications in energy intensive sectors with a high heat demand or for use in district heating schemes for residential areas.

In rural areas of industrial countries, heat demand tends to be too low to warrant a CHP-based biogas plant. For these areas, purification to natural gas quality is a more common option adopted. The purified biogas is fed into the natural gas transmission network so it can be used at another location for electricity and heat generation. Purified biogas can also be used in the transport sector, in vehicles converted or designed to run on natural gas.

Again, industrialised countries dominate when it comes to the use of electricity generation from biogas. Indeed, OCED countries account for 95% of the market, producing around 40.4TWh from biogas plants. Installed biogas-powered capacity is estimated to be about 5.8GW worldwide. Assuming a growth rate of 5 % in 2011, OECD biogas electricity generation is now around 42.5TWh, while installed capacity is up to around 6.1GW.

With about 15TWh produced in 2010, Germany leads the market, followed by the US (9TWh) and the UK (6TWh). Generally across the EU, biogas use is increasing (driven the Renewable Energy Directive, which includes renewables heat and transport related targets as well as electricity generation). Broad growth is expected across the EU, but most notably in Italy, France, Spain, Czech Republic, Hungary and Slovakia.

Growth is also expected in Thailand and Malaysia, while in Africa and, to a lesser extent, the Middle East, interest in using biogas (especially landfill gas) for energy production is also increasing.

Liquid fuels

To date, there is limited use of liquid biofuels for electricity generation. Instead, the transport sector is the main market. However, in 2010 about 5.1TWh of electricity was produced from liquid biofuels, mainly via CHP plants in OECD countries. The main markets were Italy, with around 2.4TWh, and Germany, with 2.1TWh. Electricity production from liquid biofuels has however stagnated in recent years, so output is expected to remain at the 5TWh level in 2011.

Driven by goals under the Renewable Energy Directive, Germany plans to extend its use of biofuels, mixing it with conventional, oil-based fuels to make a so-called blended fuel. It aims to double the share of bioethanol within petrol from 5% at present to 10%.

This “new” blended fuel, dubbed E10, is now sold at petrol stations across the country. However, so far E10 has not achieved the sales hoped for, with the public resistant to change and vehicle manufacturers refusing to uphold guarantees if the blended fuel has been used.

 Part seven (out soon):