Eventually, most people seem to realize there is an energy crisis looming, yet one may wonder, where are the alternatives? Why do we see so little renewable energy installations, apart from a few wind farms?

• Is the technology not there?
• Is it unreliable?
• Is it too expensive?
• Is there too little government support?

E.g. passive solar heating has been described first by one of the old Greek scientists, over 2000 years ago. Wind and hydro energy has been used for many hundred years, especially in mills, and for the last 100 years in electricity production. Today's wind- and water "mills" are more or less the same, with small improvements such as better electronic controls and fewer wearing parts.

One of the newer technologies is photovoltaics (solar electricity). While the effect had been discovered in the 19th century, nobody heeded it until the advent of semiconductors half a century ago. It then got a boost from space technology, and since the 70s it is available for terrestrial use. Since the 80s, solar electric panels, as well as solar heating panels, are one of the most reliable products one can buy with an expected lifetime of over 50 years without maintenance.

The big 'killer' for renewable energy in the 20th century was really the availability of cheap coal, oil and gas, together with heavy government subsidies for expanding the grid and connecting to it. In nearly every rural area of Ireland I worked in, people told me "there had been a wind generator (or hydro turbine) over there back in the 50s, but they closed it down when the ESB came in". To make it worse, the ESB held virtually a monopoly for buying electricity for decades and offered small hydro producers too little to make the operation viable. Today, the grid is in principle open to everyone, but still renewable electricity producers find it hard to compete with coal, oil and gas fired power stations. This will however change shortly with oil supplies running down.

But what can be done NOW?
Apart from large wind generators, which operate competitively in a good location, there are four areas where small systems can be viable at today's energy prices.

One is solar water heating. While their output is concentrated in the brighter half of the year (March to September), they can replace running boilers or immersion heaters for hot water in summer, where neither of the two run very energy-efficiently. Apart from private houses, they are very appropriate for any commercial premises requiring hot water - e.g. hotels / guesthouses, camping parks, swimming pools. With a payback time of 12-15 years at today's fuel prices, they are not seen as hugely profitable, but as an insurance against future price rises.

The second one is small run-off-the-river hydropower systems. These are obviously confined to suitable sites, the best being mountain streams with a steep gradient. But here, they can work out very cost-efficient; especially, when the power produced is being used directly rather than sold through the grid. (You may get 6c/kWh for selling power, but you can replace buying power at 12-16c/kWh !).

The third one is electricity in remote locations (islands, mountains) without grid connection. Up to recently, this niche was the only application for solar electricity (PV). While the initial investment is high, it may still be a lot cheaper than connecting the place to the grid. (But again, the government subsidises grid connection only.)

The fourth one is not new at all: Biomass; traditionally called firewood. As long as there is not more cut than there is growing, firewood is renewing itself. And those who find cutting and handling firewood inconvenient can now get wood pellet boilers, which even burn more efficiently. A large-scale use of biofuels however could make available land scarce again; therefore I feel it should be used in conjunction with best energy conservation and solar energy.

A more widespread use of PV as well as small wind power depends on prices for it coming down and, even more importantly, a straightforward procedure for grid connection and metering. Now, once the grid is almost everywhere, grid connection works out a lot cheaper than battery systems in the long run. Also, it can better balance out fluctuating input, a drawback especially with wind power. Technically, grid connection and 'net metering'* are very straightforward: there are no extra administration costs and it can even ease the load on the ESB grid, which is becoming a problem in many areas.

In short: future energy prices will make renewables happen, unless governments intervene the wrong way; but we may as well start now!

* Net metering: the electricity meter runs backwards when the PV, wind or hydro system produces more power than what is being used on-site, so you pay only for the 'net' units you buy from the grid.