FIRST solar thermal Power Plant in Southeast Asia

As posted in my December 2011 entry: Parabolic mirrors that produce electricity, harnessing of energy is done indirectly by converting concentrated sunlight into heat. This heat will be used by a steam turbine or a heat driving generator to generate electricity.

Hence, the name solar thermal.

TSE1 plant in Thailand. Credit: CSP Today

It is a known fact that Thailand is ahead of all other Southeast Asia nations in terms of renewable energy initiatives. Recently, Solarlite - a German concentrated solar power technology provider - commissioned Southeast Asia's first direct steam generation parabolic trough plant called TSE1, to supply 5 MW of electrical power to Thailand's public power network.

TSE1 is the first of 15 CSP stations planned by Thai Solar Energy and when completed, total generating capacity will be 135 MW. There is a feed-in tariff, FIT, scheme in Thailand for small energy generation system of up to a capacity of 10 MW.

Similar to Malaysia's initiative through SEDA, Thailand's aim is to give opportunity to people in the remote areas to participate in electricity generation, especially from renewable sources.

What makes Solarlite installation in Thailand special is that this is world's first in Direct Steam Generation. Instead of heating a thermal oil, the solar energy heats up the water that flows through the parabolic trough collectors receiver tubes. Therefore, no heat transfer oil is needed and heat exchanger - one of the expensive components in the CSP plants - becomes redundant. This means that the CSP plant is more ecological and safe as it uses only water.

Second plant, TSE2 is currently under construction and all of Thailand’s current Solar Program is targeted to be completed by 2015. New program was recently announced, under which 2GW of solar capacity from both solar thermal and Photovoltaic must be installed by 2020 as part of Thailand’s commitment to sourcing 25% of it total energy requirement from renewable energy sources.

Solarlite's solar thermal parabolic trough plant in Thailand. Image credit: solarthermalmagazine.com

The TSE1 plant does not have energy storage capacity as it is not economical to install storage system for small plants. Meaning, every time clouds shade the plant there would be power outage. Furthermore, Thailand's FIT which has a framework of 10 years and maximum 10MW of plant generating capacity deprive Solarlite the benefit of economic of scale. The current feed-in tariff for energy generated from CSP is 11.5Baht/kwh (about RM1.12/kwh).

Compared with Thailand, FIT scheme in Malaysia is structured to run longer i.e. up to 21-year with more competitive rate, especially Solar PV. This scheme is however limited to only 4 sources of renewable energy, not including CSP. To recall, the four energy sources that enjoy the Malaysian FIT scheme are Solar PV, Biomass, Mini Hydro and Biogas.

Solarlite in an interview with CSP Today stated that if they can make it and be successful in Thailand, they can make it anywhere, and that include Malaysia. They have the advantage of producing components in Southeast Asia (Thailand) and with the right approach with our government, there's no reason why can't CSP be implemented in our country. We can start with the remote areas to power up the rural population.

Why not!


Abbreviations
CSP - concentrated solar power
FIT - feed-in tariff
PV - photovoltaic
SEDA - Sustainable Energy Development Authority (Malaysia)

Parabolic Mirrors That Produce Electricity

Although not the main source of today's electrical energy, people would probably be more familiar with the term solar power (Solar PV) now compared to 20 years ago. In solar photovoltaic, light is converted to electricity directly using photovoltaic panels. This is one way, and the most conventional means of harnessing energy from the sun.

The other method - not yet as popular but gaining momentum - is through Concentrated Solar Power (CSP). As it name suggests, similar to Solar PV, the the sun is the source of energy but harnessed indirectly. Parabolic mirrors are used to concentrate sunlight onto receivers and convert it to heat. This heat will be used by a steam turbine or a heat driving generator to generate electricity.

Image from Desertek-UK

In a more technical terms:
In CSP plants, long, parabolic silvered glass mirrors are arranged in troughs that track the sun as it moves through the day. The solar radiation hitting the mirrors focuses on metal heat-absorbing pipes, encased in glass, at the focal point of the mirrors, where it warms synthetic oil to temperatures of 350 - 400 degree Celcius. The super-heated oil is then pumped down the pipe to a central power block where heat exchangers absorb the energy to create steam that drives a steam turbine and generate electricity.

In 2010, Solar PV has a total global capacity of 40,000MW with another 24,000MW expected in 2011. In comparison CSP total installed capacity in 2010 stands at 1,095MW while at least 6,200MW more has been initiated in 2011. This shows that Solar PV is way ahead of CSP in terms of global acceptance.

Is it better than using the normal solar cells to convert the light to electricity directly? Unlikely. CSP is probably more of complementing Solar PV than a direct competitor. Due to the thermal storage capacity of the CSP system, electricity can still be generated during cloudy days unlike photovoltaic.

It is good to diversify, especially if it is sustainable and one that does not harm mother nature.