CAPM and Geothermal Energy Projects in the Philippines

Aside from the relatively high cost of developing geothermal energy sources, there is another challenge that the private sector deals with in developing the said renewable energy in the country: regulatory challenges, particularly the tariff setting mechanism.

CAPM Formula. Photo from

CAPM Formula.
Photo from

In my previous post, I have discussed the Capital Asset Pricing Model (CAPM). The CAPM assumes that investors will choose the assets that will yield higher returns over risk-free assets that provide a premium. The CAPM developers used Beta to measure the premium for the risk of an asset, assuming that using the entire market can reflect accurately the correct return of the risk of a particular asset

The Energy Regulatory Commission or ERC uses the CAPM in the tariff setting scheme.

Under the CAPM, the cost of equity is calculated based on the following formula and parameters:

re =rf + betae x MRP


re = nominal cost of equity

rf = risk free rate for the Philippines

betae= the equity beta for benchmark generation company

MRP= Market Risk Premium (MRP)

Both the risk- free rate and market risk premium are based on the historical ERC approvals.

However, the ERC reportedly uses the same beta of (~1.03) for the tariff setting of power plant projects regardless of the technology without consideration to the risk profile of the power plant project. This means that the value of Beta is the same for coal power plants and geothermal power plants. And here lies the problem.

Using the same beta for coal-fired power plants for cost recovery is unfair to geothermal developers and does not reflect the proper conceptual use of the CAPM.

Let’s look at the case of two power plant projects—a geothermal and a coal-fired power plant.

The ERC approved a coal-fired power plant project of 110 megawatts in Mindanao. Its total project cost is roughly P14.6 billion.

The ERC also approved a 40-megawatt geothermal power plant with a total project cost of more than $207 million dollars or roughly P9.1 billion pesos. (at $1=P44 Exchange Rate).

Both projects are financed by 70 percent from loans and 30 percent through equity.

In our above examples, it is obvious that geothermal power plant project costs more. The coal-fired power plant has a capacity of 110 megawatts and costs P14.6 billion, whereas the geothermal project has 40 megawatts capacity but costs around P9.1 billion.

Of course, the costs of geothermal exploration and power plant construction are higher than putting up a coal-fired power plant. But, again, it is wise to invest in geothermal energy since it is not subject to price fluctuations, unlike fossil fuel-based plants.

As mentioned in my previous post, the private sector undertakes high risks because of the exploration required to develop the geothermal sources. Geothermal power projects entail exploration including the drilling of wells to determine if steam is available. Test drilling alone can cost $5 million per hole, and there is no guarantee that steam is available from the hole being explored.

In fact, according to a study conducted by the International Finance Corporation, roughly only 60 percent of the explored holes worldwide turned out to be successful.  This means that geothermal exploration is a high-risk and expensive undertaking. Exploration alone costs more than half of the total project cost for geothermal power plant projects.

On the other hand, coal-fired power plants only require the importation of the fuel and the power plants structures that are almost uniform.

The ERC uses the beta for coal (~1.03) to determine the return on equity for any project regardless of the risk profile.

Arguably, ERC’s choice of using the same Beta for coal and all other power projects is an incorrect application of the CAPM. Plus, of course, it is most unfair for renewable energy developers especially for geothermal energy developers in the country because they bear risks that are higher compared to the risks undertaken by coal-fired power plant owners.

The Beta in the CAPM, again, measures the risk. It follows that an asset, which has a higher risk profile, should have a higher Beta value. Under the CAPM, the riskier the asset is, the farther the asset is from having a Beta that equals to 1. Simply put, the value of the Beta used for the computation of the tariff should reflect the specific risks assumed by that particular asset in relation to the entire market.

The value of the Beta should reflect the risk of the market since CAPM assumes that the entire market can reflect the correct return of the risk of a certain asset. It is then sensible to use a Beta that reflects the premium for the specific risk of investing in a geothermal energy power project in relation to the entire market rather than a Beta for a different type of asset or technology, in this case, the coal-fired power plant.

It is therefore, logical that a geothermal energy power project will have a different value for the Beta, a higher value at that since geothermal development is riskier than a coal-fired power plant project.

The geothermal power plant projects should be given a higher yield than coal-fired power plant given the higher capital and risk exposure of the private developers. This is especially true these days where the government no longer shells out money for the exploration, but rather leaves the private sector to do its own exploration of geothermal sources, which comes at a high price.

Unfortunately, the ERC does not see it this way as it uses the same Beta for all power plant projects.

So, what incentives do geothermal power plant producers have to invest their money on such a risky undertaking when they are unable to obtain the required return given the incorrect valuation of the risks involved in these projects?