Speaking in the aftermath of European Commission proposals to protect strategic sectors from exploitative buyout behaviour, Sarah White, head of energy policy in the department of communications energy and natural resources, said private equity groups often express interest "and occasionally come in to kick the tyres" of Irish assets, but will continue to leave empty-handed.

Australian investment bank Macquarie is one such entity understood to have contacted the Irish government in relation to energy infrastructure last year.

Macquarie, which manages $30bn worth of equity in infrastructure projects, would neither confirm nor deny it has made representations to the government, although it's understood contact was first made early last year.

"We carry on discussions with all sorts of people all over the world, " said a spokeswoman. "An energy network might or might not be a part of those discussions." Macquarie has an Irish office in Dublin where the main business interest is currently IT leasing according to the company.

In recent weeks the governments of Britain, Spain, the Netherlands, Belgium, Sweden, Finland and Romania, have written to the European Commission in an attempt to influence proposals on energy due to be set out by Brussels in September.

"The European debate is of great interest to us in terms of disentangling transmission assets but who owns them is a different debate, " said White.

She said this approach sends a strong signal to possible investors in power generation that Irish transmission networks will be operated transparently "without any vested interests having an upper hand."

Responsibility for transmission will be transferred to Eirgrid and the Commission for Energy Regulation will "keep its foot on the neck of both Eirgrid and ESB, " said White.

THERE is already one private equity investor in the all-Ireland energy network in the guise of Bahraini outfit Arcaputa, formerly know as the First Islamic Investment Bank, which completed a $4.2bn acquisition of Northern Ireland electricity utility Viridian in December 2006.

Irish industry observers said they were surprised private equity houses enquired about state-owned assets, particularly as there is a public commitment to keeping the national grid in state ownership, even after it is transferred from the ESB to operator Eirgrid.

One observer said the decision had been made because the government felt it necessary to provide a "level playing-field" for electricity companies operating in the market.

The ESB's unions, currently battling government over the transfer of the grid, have also expressed surprise at revelations of private equity interest.

"This is way, way off government policy and any difficulty they would have with transferring the assets would be nothing compared to the difficulties they would have if they tried to sell it, " said the TEEU's National Industrial Officer David Naughton.

Although the message coming from Adelaide Road is that electricity transmission and distribution networks are not and never will be on the market . . . for private equity or others . . . there is a realisation that massive investment will be necessary if Ireland's infrastructure is to be modernised and futureproofed.

Smart metering is one possible upgrade allowing supply and transmission networks to discern exactly how much electricity household appliances consume. A new report from Datamonitor predicts more than 40% of European households will have smart meters by 2012.

Data broadcast on a smart meter network from households would include information such as time of use, tariffs, tampering and outage detection, according to analysts. This means the day of the utility electrician coming to read the meter could be numbered. Another possibility no doubt distasteful for unions.