A major overhaul is needed to avoid abrupt, irreversible climate change. We must turn to a wide range of technologies for a secure energy supply in the years ahead.
At the Chamber of Engineers annual national conference last week, a number of presentations looked at how future energy demand could be met while taking the environment into account.
Energy demand is expected to continue rising worldwide at a considerable rate, putting tremendous pressure on oil supplies.
Enemalta chief technical officer Peter Grima gave an overview of the corporation's plans to ensure a sustainable supply of energy. He said that while the corporation had to meet consumer demand it also had to encourage them to reduce consumption.
"We have a lot of environmental legislation that we have to comply with and we have to comply with it all," he added.
Enemalta has run trials using biofuel in power station burners, but supply cannot meet demand and the price is on the increase.
John Borg, a researcher and lecturer from the University of Malta's Faculty of Engineering, has been investigating the performance of photovoltaic systems in the Maltese islands. Six systems in Malta and Gozo, all using the same hardware and inverters, showed variations in efficiency, depending on conditions. An oversized inverter made the Malta Environment and Planning Authority's solar panels less efficient, and in other cases the inverter was undersized, again reducing efficiency.
Panels installed at Għarb showed a 24 per cent loss when not cleaned often enough. The Armed Forces of Malta keeps a monthly checklist recording energy output and frequency of cleaning for its photovoltaic installation at Luqa.
In some cases, the roof panels were not easily accessible or there was no water readily available for cleaning. In one case, the panels were made less efficient because of shade cast by airconditioners that were installed afterwards.
To stimulate more photovoltaic installation a better selling price to the grid is needed. Work is ongoing with photovoltaic and inverter manufacturers to develop a small molded system.
Formulating regulations to ensure that panels installed in sunny spots are not cast into the shade when a block goes up next door would also help safeguard payback on investment.
Tonio Sant, director of the Institute of Energy Technology, spoke on the current status of offshore wind potential. Deep-water wind farms far out from Malta's shores have been ruled out. A difference in average wind speed of four metres per second makes this technology more suitable for northern Scotland than for Malta.
Floating platforms are not expected for another ten years unless there is a technology breakthrough. Design is still at the early stages of modelling the complex interaction between waves and the structure.
Even though wind energy is among the less expensive options, costs increase radically for offshore turbines with every metre of sea depth and distance from coast. Well-proven technology for wind farms at depths of over 30 metres does not yet exist although a German firm is working on developing structures suitable for twice that depth.
Energy generated by offshore wind turbines is more expensive than having them on land but they can still be competitive and there are some advantages.
Turbulence reduces the performance of turbines and increases fatigue on them, which in turn reduces their lifetime. This is less likely to be generated on land than at sea. Unless turbines are spaced well apart, aerodynamic losses from the wake can run from five to 20 per cent.
A large wind farm in shallow waters offshore could benefit from economies of scale. The cost of constructing a wind farm is expected to come down as more suppliers enter the market.
Assessing wind resources by taking measurements over time from a high mast reduces uncertainty. Investors demand a very high resource assessment. Measurements are also needed to determine wind park design and type of turbine.
When developers seek funding from financial institutions they have to provide detailed reports. The banks employ experts to assess their reports and accept only a 10 per cent margin of uncertainty.
The largest commercially available turbines today have a diameter of 126 metres and capacity for generating five megawatts per tower. Designers are working on 10 megawatt turbines, mainly suitable for offshore. A shortage of installation vessels for turbines sited offshore, and a rise in the price of steel (wind turbines are 90 per cent steel) has kept the price high.
On land, massive cranes and trailers are needed and roads to access the site must have adequate curvature to allow the huge components to be transported to the site. On a smaller scale, more information is needed on wind conditions in the built environment to develop our potential for renewables in an urban setting. Solar energy is still too expensive without large subsidies even though costs have come down by 30 per cent in the past few months. Most renewable sources of energy will need more government support.
The draft national energy policy issued last week makes only vague references to promoting renewable energy without much of a commitment beyond existing incentives.
Current capping of electricity bills for commercial activities such as hotels is a clear disincentive to conserve energy.
More attention needs to be given to combined heat and power systems which can generate electricity and recover energy for heating or cooling while saving on transmission losses.
It is not clear who is enforcing which regulations. An agency for climate change and renewable energy is needed which would provide one team with a holistic plan rather than multiple documents which overlap.