“BLACKOUTS!” This is the threat that some quarters are using to argue the case for more coal-fired electricity production, i.e. CT Power. Environmentalists and local residents are protesting against this but have yet to present viable alternatives. What is the real situation and do we have other options?

Future demand

Recently, peak demand for electricity reached 410MW – an increase of 90MW in 10 years, but 74MW less than the CEB was predicting in 2003. This has avoided the necessity of adding the equivalent of three quarters of CT Power’s 100MW capacity. Clearly the best option for generating electricity is not needing to in the first place. Can we do that?

Industry uses almost a third of the electricity we produce but pays only half the price charged to other consumers. Hence, it has little motivation to reduce consumption. Government loans could help stimulate investment in efficiency with costs recovered through higher prices, while keeping bills constant.  Similar incentives could help families purchase more efficient appliances, while retro-fitting buildings to lower their energy use would also create a plethora of “green jobs”. Surely it makes more sense to invest in saving electricity than producing more of it?

Coal power-stations last at least 30 years. It is difficult to predict how life will be so far into the future, but current trends can point the way. Many of today’s “zero-emission” buildings generate their own electricity using solar panels and store it until needed. If all buildings did this, demand for centralised electricity production would decrease significantly. Can we imagine this happening by 2040?

Blackouts

Even the most sophisticated power-stations break down, causing an instantaneous drop in generation. Electricity supply must always equal demand so, if replacements cannot be added quickly enough, parts of the grid must be disconnected to restore balance – resulting in regional blackouts. The CEB has a gas turbine on standby to help protect against this. It can reach full power quickly but is very expensive to operate and maintain. Incidentally, this is a hidden cost that the private sector’s power-stations don’t pay for, it is borne by the CEB and passed on to consumers.

In other words, blackouts are not caused by a lack of capacity, but by our reliance on large power-stations that can stop without warning. In the UK, the largest installation is about 2% of peak demand, but in Mauritius, CT Power would be over 20% – and larger than the gas turbine. Hence, the proposed coal power-station might actually increase the risk of blackouts, not reduce them. Would it not be much better to have a large number of relatively small units than a small number of large ones? While they would still breakdown, their impact on the system would be significantly less. Unfortunately, coal power-stations do not come in small sizes.

Flexibility

Demand for electricity fluctuates throughout the day and coal and bagasse power-stations are not flexible enough to keep up with the changes. Hence, even if CT Power is constructed, the CEB will still need to operate its expensive oil/diesel-based units, particularly during the day time. The CEB’s approach to small power producers, such as the 2MW biogas unit at Mare Chicose landfill, is to accept whatever electricity they produce. However, it could be switched on and off instantly at the CEB’s request.

If 25 such power stations were managed collectively as a single unit, the CEB would have at its disposal 50MW of very flexible capacity for which it could afford to pay premium prices, as happens in the UK. This flexibility could also allow the integration of more wind turbines, whose output fluctuates with the weather and hence, on their own, are not a viable alternative to CT Power.

Biogas

As well as Mare Chicose landfill, we are also generating electricity from biogas at St Martin water treatment plant and a unit at a diary farm is planned. It can also be produced from our green waste – simply by converting it into compost in sealed tanks rather than the open air. The largest potential source is the 10,000 hectares of abandoned sugar cane fields which could be planted with high yield crops.

Sustainability

There are two well established, viable alternatives to coal. Both reduce our dependence on imported fossil fuels and hence our greenhouse gas emissions. They are perfectly compatible with the government’s MID project, so why aren’t they being seriously considered? Perhaps those saying “NO! to coal” should add “YES! to efficiency and biogas”…