Oh great.
They are going to sell off the power system and then get blamed when the new operator runs it into the ground to extract the maximum value from it with minimum investment.
Possibly, although the other way of looking at it is along the lines of;
We have a relatively small power network (spead over a very large area) which costs us a lot to run and have trained staff sat waiting for things to go and fix.
There are several companies who run other power networks (SSE, UK Power Networks, WPD, etc.) who have trained staff also sat waiting for things to go and fix.
Therefore why not have less people sat around waiting to go and fix power networks with all the other "savings" (such as less depots, less vehicles, etc.) by selling our network to them. There could even be ways in which the rail network's power supply network could be used to reduce the costs of supplying houses and businesses.
Although I can see your concern the power supply networks who supply the lines to our houses and businesses haven't done that. For the simple reason that to do so wouldn't be profitable. Even when there are power supply problems (lines brought down, transformer issues, etc) they go and sort them out quickly.
Yes some have merged to minimise their costs, so you have WPD (historical West Country) covering Wales and The Midlands as well, but they do appear to do a good job and invest in their networks.
It could lead to an interesting senero (going towards the opposite extream) where they could decide to extended their network as it would provide a significant enough of a return to justify doing so. For instance, if by putting in an extension it allows them to make a significant saving and/or provides them with a new market.
However I can also see them looking for significant payments to making alterations to their network.
