Solar Power Part I


  • 90% of the solar panels in the market today are made of polycrystalline Si. The remaining 10% are made of inorganic materials.
  • The largest demand is Germany and the largest supplier is China.


  • Solar is growing at the fastest pace than other major renewable energies. Although its capacity factor is the lowest.
  • Cost wise, the PV system has dropped below 1 USD/W. The non-modular cost such as maintenance fee, racking, wiring, inverters remain pretty much the same so the falling cost of modules are the main contributors to the falling price of solar PV.

Technical words

  • Irradiance = power per unit area (watts per sqm)
  • Spectral power density = incident power per unit area and per unit wavelength
  • The sun is a black body radiator (which is not reflective and absorbs all light). The higher the temperature of black body radiator, the higher the photon energies.
  • Solar spectrum is distributed 9% UV, 44% visible range, 47% infrared.
  • The amount of irradiation is affected by things like atmospheric mix (CO2, oxygen, water).
    • 20% of irradiation is reflected by clouds, 6% by molecules and 4% earth’s surface.
    • 19% absorbed by earth’s surface
    • Total lost = 49% of irradiation when hit on earth’s surface.
  • Solar irradiance is expressed in sun hours where earth is exposed to 1000watts per sqm. Places like Spain with more sun has around 4.2 sun hours daily.




What Donald Trump’s presidency means to energy & environment

GOP 2016 Debate

The Trump presidency was not great news to climate change supporters. It was not the outcome many hoped for, and could potentially pose a significant threat by demolishing any progress made in the Obama administration for climate and environment.

Calling climate change a hoax that the Chinese fabricated to gain unfair advantage, he vowed to pull out of the Paris agreement on climate change first thing he comes on board. He will also remove any form of carbon taxing and deregulate any bans on drilling or fracking. Many coal workers voted for Trump in hopes that he can revive the coal industry to its glorious past. However, this proves to be unrealistic and likely impossible.

Renewables aside, coal is no longer competitive on any front. Successful fracking for natural gas in tight shale formations has enormously increased America’s natural gas production, keeping prices low, and outcompeting all other energy sources, especially coal and nuclear. It doesn’t make a lot of financial sense to expand coal use again within the United States.

As for the renewable energy sector, wind companies saw their shares tumble the first few days after the election. Fears have been building up in the renewable industry that his win means a big loss to them. Trump has a personal history with some wind projects which he thinks are against the advancement of his private businesses. One example is his fight against wind farms built across his golf course in Scotland, because it “blocked the views” of his golf course.

Tax credits are the lifeblood of renewables. Concerns about Trump rewinding the tax credits and hurting the renewable energy industry have been raised but may not crystallize in the way we envisioned. The Republican-controlled Congress already extended the renewable energy Production Tax Credit to 2021, and there also are various state tax credits and the Renewable Portfolio Standards — laws requiring a certain portion of a state’s power generation mix to come from renewable sources — to consider.


Pure economics will dictate the fate of the futures of renewable energy. The price of wind per MW is already cheaper than coal and solar is quickly catching up. Time-wise, it is also smarter to invest in solar farms as they take only a few months to come online where as coal-fired plants can take up to years. Solar and wind will continue rising at a fast pace in the next few years, and their growth will be driven mostly by state rather than federal policies. Even without tax credits, their prices are falling, making them naturally competitive.

However, let’s remember: all talk of Trump’s actions may deem futile as his words are rarely gone to fruition at the end of the day. Case in point: he has started reconsidering his stances on climate change and expressed that he would like to see “clean air and crystal clear water”.

Solar’s future : wins and loses

An optimistic projection states that by 2030, the solar generation capacity could go up to 250GW. This is a leap of over 100 folds since 2010 where the capacity was only 2GW, meaning that the share of energy pie from solar would rise from 1% to 10-15%. Price wise, cost of solar is now around $1.50/watt from $3.50/watt in 2010.

Here’re some cheerful indicators:

  1. Solar cost is only going to fall more as panels become more efficient and intense competition forces costs of solar projects down.
  2. Reforms in different states on energy are happening. NY’s Reforming the Energy Vision (REV), for example, focuses on creation of distributed service platform providers (DSPPs), where utilities will effectively host mini-marketplaces for energy to and from distributed energy resources.
  3. The Clean Power Plan enacted in Feb 2016. This will force polluting plants to cut down their emissions as well as encourage each state to have their own plan to achieve the emissions targets and encourage cleaner energy.

And then there’re the less sunny reality checks:

  1. The expiration of the investment tax credit (ITC) in 2016, the incentive scheme that applies around a one-third discount off the cost of installing solar and solar-plus-storage. Currently petitioning for extensions.
  2. No ability for solar to be fed into grid based on demand as now it’s still relying on low-storage, not so stable loads which are pretty much at the mercy of the sun’s variability.
  3. The rush to build and supply solar panels may cause an over supply of panels and force solar companies out of business if demand is unable to catch up with supply.

Below is a chart of current state of clean electricity breakdown in USA. Wind is the fastest growing sector and solar is still growing but remains below the levels of wind and hydro power.

San Francisco’s mandatory solar panels in 2017

So San Francisco passed a new law mandating all new buildings below ten storeys high to install some form of solar power: either solar PV or solar thermal. This will come in effect from 2017. This is a welcoming news (any governmental step towards more clean energy is a welcome gesture), indicating the city government is showing vested interest in fulfilling the promise of 100% renewable power in 2020.

Let’s take things apart a little bit and put things in perspective. San Francisco has a land size of 130km2, and around population of 800,000+. The new law is estimated to save around 27k metric tonnes of CO2 / year or equivalent of lifting off 5000+ cars on the road. The average San Francisco-ian uses about 7 metric tonnes of CO2 annually which means that this law will result in an average of per capita reduction of 0.4%. So clearly, the amount of reduction of CO2 is sort of negligent.

There are two things that could be done to improve this:

  1. To increase the mandate of having 15% rooftop space for unblocked sunshine to a greater percentage to say 30% or 40%. This will raise the capacity available for solar panel infrastructure.
  2. To solve the problem of energy demand by building taller residential buildings and encouraging people to move more into city. This will kill two birds with one stone: reducing long-commute hours and reducing apartment unit size which means less energy use.

So I would say if the anyone is really serious about tackling climate change, it would be better to look ahead and consider the bigger picture. That said, let’s hope for more good news to come.

Singapore’s Future in Solar PV

Energy Studies Institute organized a one-day conference which brought together experts from government agencies, research institutes and solar companies on a common discussion topic of the future of Solar PV, internationally, regionally and locally.

The IEA started the day with a comprehensive discourse on the trends in solar energy for the next few decades, outlining the fastest growth in capacity of both solar and wind energy in countries like China, Japan and USA. Outside of Europe and in emerging economies like Africa, there has been significant reduction in cost of capital, allowing speedy expansion of solar. Key elements to success in solar include good financing and PPAs (Power Purchasing Agreements).

The presentation was substantially flavoured with insightful statistics and figures backing up the predictions: Projection of solar energy growth of 400 GWp to 500 GWp by 2020 and 560GWp by 2025 to meet climate change objectives. And with conservative calculations, to reach 16% of energy market in 2025. However, further actions are needed for the estimations to be precipitated. For example, system integration, policy framework and financing as well as government setting aside long-term targets to help finance, distribute and facilitate uptake of solar in a larger scale.

Solar leasing is a crucial way of encouraging the uptake of solar installations. Through shifting of risks and financial burden of capital costs to the lessor, building or house owners have an added incentive to join the game. Not only are the modules financed by investors, lessees get to reap rewards of harvesting solar energy by being green with zero or low cost.

Currently in Singapore, town councils are managing the solar leases with HDB flats and paying for the power generated at lower than retail rate. The latest tender awarded Sunseap with 38MWp for 680 HDB flats and HDB-owned buildings with the cost fully borne by the developers.

The situation in Singapore
Phoenix Solar came in to shatter myths hindering solar developments in Singapore, busting old-aged tales of how intermittency will cause solar power to be unreliable to deploy on national scale. Blessed with plentiful rain throughout the year, intermittency during days of storm can cause intensive drop in aggregate output. However, data showed that the average monthly fluctuation is around 20% which was claimed to be an insignificant cause for worry. Now, installation of solar panels is decentralised and diverse across Singapore, totaling around 9 MWp. It was predicted that solar could contribute up to 2 GWp by 2025 (1/3 of total demand in Singapore) and 600 MWp by 2020, as grid parity has already been achieved ($0.23KWh for solar and $0.21KWh for gas).

Singapore is particularly blessed with government support and efficacy in facilitating the growth of solar industry locally. In countries such as Thailand, hindrances such as lack of government funding, prohibitive rules and inefficacy in pushing out key projects remain as reasons for falling behind. For example, inflexible rules such as the need for a factory license before installing a solar panel with 10KWp capacity occludes solar PV installation on residential roof tops.

The top three PV Success factors include having i) a good business model, ii) cost of equity, debt and construction capital and iii) refinancing and/or exit plans. One of the ways to achieve ii is to get investments. Though solar PV is already traded as a commodity in the markets and repackaged as financial instruments globally, Singapore does not have a large enough pool for securitization. Thus, one of the ideas which sprang up in the conference was to make Singapore a secondary market for the region.

From a regulator’s standpoint, their role was to reduce as much barriers as possible for solar to enter Singapore’s market. Energy Market Authority reduced the number of days from 27 to 7 days to join the power grid locally. It also created a 1-stop PV information sharing website for people to exchange ideas and knowledge. To hedge the problem of solar intermittency affecting stability of power in Singapore, the Intermittent Generation Threshold (IGT) has been set. Basically, this implied the maximum amount of solar energy produced which does not incur additional cost to carry on the existing system. The IGT is now 600MWp (previously 350MWp).

The Future of PV
Due to the unique constraint of land area in Singapore, there needs to be innovations in the usage of solar PV as an energy source. These are already present and are in stages of testing and development, including: floating PV panels (5KWh by Phoenix Solar), using Pulau Semakau as a PV bed as currently they are using diesel to generate power for waste facilities, and Building Integrated PVs (BIPVs) whereby solar panels are placed vertically on buildings like windows. However, some challenges like time-sensitivity of BIPVs and high installation costs remain to be resolved. Without subsidy from government, solar companies need to think of ways to build business models which will thrive in an island with a small land area, in order to propel a faster growth of solar industry here.

Singapore removes cap for solar energy supply to grid

Great news for solar! The energy authority decided to remove the 600 megawatt-peak (MWp) cap of solar energy that can be supplied to our national grid.

Why was there a cap in the first place?

  • Softens the impact on the grid in case of unpredictable reduction in solar supply caused by factors such as cloud covers.
  • Reduces the reliance on reserve powers.

Why are they removing it now?

To encourage more generation of solar energy in the Singapore energy market.

What are the impacts?

  • For companies, there may be added costs due to the need for increased reserve capacity
  • Smaller consumers who install solar generation sources will find it easier to be paid for supplying excess electricity they sell to the national grid.
  • Come 2015, consumers can be paid the energy cost of electricity they export into the grid, currently, 25.68cents per KWh directly through SP.

What proportion is the solar energy output in the overall scheme?

  • The total power generation capacity is 10,000 MW which is more than the peak electricity demand of 6,000 MW.
  • Solar output would then be around 10% of total.
  • In Singapore, the only intermittent energy source connected to the national grid is solar. 85% of the energy it uses is generated through natural gas.

Sources: ChannelNewsAsia, abc carbon, pacific light