How to have cheaper diesel

Frequent brownouts are plaguing Mindanao these summer months. Here in Davao del Sur, brownouts occur two to three times a day, the longest usually lasting an hour.

With these brownouts, you would think that your monthly electricity bill would go down. On the contrary, it has gone up, the reason being that the generation charge has gone up by almost P1 per kilowatt-hour. Obviously, diesel-fired power plants and barges are being used to the hilt to provide electricity.

The government says it has no control over the price of diesel. But something can be done to reduce the purchase cost of diesel. One way is to use a reference temperature as basis for computing the volume of diesel for which the power companies are billed with.

In cold countries such as the United States, the reference temperature for diesel is 60 degrees Fahrenheit or about 16 degrees Celsius. In tropical countries such as the Philippines, the reference temperature is said to be 85 degrees Fahrenheit or about 30 degrees Celsius. This is more or less the average temperature during the nonsummer months. When the temperature rises above the reference temperature, the volume of diesel increases but the heating energy you derive from it is reduced. The reverse is true when the temperature goes below the reference temperature—the volume of diesel contracts, but the heating energy increases.

It is the heating energy that you pay for diesel. During these hot summer months when temperatures could go up to 36 degrees Celsius, you derive less heating energy from, say, a tanker delivery of 20,000 liters diesel than from the same volume delivered during the nonsummer months. With the reference temperature, a volume correction factor is applied to the 20,000 liters delivery to compensate the buyer for the reduced heating energy he derives from the diesel delivered. In other words, the buyer would not be billed 20,000 liters but for a much lower volume. The American Society for Testing Materials (ASTM) Measurement of Petroleum Products Tables provides for the calculation of the volume of diesel oil at various temperatures.

With the reduced cost of diesel, the generation charge should also go down. In the transport sector, the government should study the maximum amount of discount that should be given by the oil companies, as it may also result in lower fares during summer.

—ERNIE ADAYA,

[email protected]