O

ur country's abundant sources of energy, oil and gas for example, have been identified and utilized for the welfare of the nation for at least a century since their discovery in Sumatra. They are now becoming problems because of our long dependency on them and lack of capital and modern technology among other things. Then there is coal, another potential source of energy, the stocks of which according to experts will last for 60 more years.

Environmentally friendly sources of energy comprising geothermal, wind and solar power, may soon become primary energy sources. Bio energy, including palm oil, Jatropha curcas and other agricultural sources of energy, has begun to be exploited for the sake of energy security. Waste-to-energy systems will also play an important role, at the same time as easing the problems of waste management in large cities like Jakarta and Bandung.

Whatever the future energy mix, it is becoming apparent that coal and gas are both hugely consumptive and damaging to the environment.

Renewable energy like solar, wind and hydro on the other hand supply only a small proportion of the world's energy needs, yet they are much cleaner. The challenge is scaling them up to such an extent that they can be truly useful.

But how do you make use of nature's own energy? One option is solar roads ' using heat from the network of asphalt, roads and parking lots, in every country to generate electricity.

The theory is this: In hotter climates roads and parking lots get extremely hot. It is very uncomfortable for you to walk on them in a hot day, with extra heat radiating from the black ribbon of asphalt under your feet.

Latest reports say scientists at Worcester Polytechnic in Massachusetts propose burying water pipes a few centimeters beneath the road surface. Heat absorbed by the dark road surface will heat the water, which in turn can be used to generate electricity. As a side-benefit, the transfer of heat from road to water also helps cool the road surface, extending its working life.

Water heating is used in many current solar generation applications. The difference here is that it is visually no more intrusive than the existing road. No fields would be filled with solar energy collectors, for example.

According to the associate professor who led the team of researchers, the 'preliminary results provide promising proof of concept for what could be a very important future source of renewable energy'.

Don't get too excited though ' there are a few handicaps to overcome.

The first is finding investors for a system with untried, unknown potential returns. Some scientists speculate that the heated water simply would not be hot enough to generate high levels of energy, making return on investment too low.

And it would be quite some investment ' not just installation costs for the water piping and electricity generators, but the cost of fully resurfacing any road where the system was installed. To ensure that return on investment, you would need to be talking significant stretches of highways such as in a US state like Utah.

It could, potentially, be a technology worth pursuing on private land, but it seems like there are too many disadvantages to see widespread adoption of solar road technology.

In Indonesia, places where solar heat has strong potential such as Pontianak, West Kalimantan, a city on the equator, and also in dry and arid areas including West Nusa Tenggara and East Nusa Tenggara could probably be suitable for the application of solar road technology, also roads in remote areas where energy is quite difficult to supply.

It is the duty of researchers including those who are with the Indonesian Institute of Sciences (LIPI) and Development Institute for Technology Application (BPPT), possibly in cooperation with potential investors, to develop such a hidden but long-lasting source of energy with simple and easy applications and maintenance for remote villages.

It is time now for the inventors and creators to make use of other hidden but free and long-lasting energy sources for the welfare of the nation.

The writer, a lecturer at Atma Jaya Catholic University, Jakarta, is formerly the head of the bilateral cooperation division at the Energy and Mineral Resources Ministry.