 JOSEPHINE LISLE has barely slept since the government revealed deep cuts to solar panel subsidies three weeks ago.  The 71-year-old put down a ?4,500 deposit this summer on 16 panels to go in a field next to her East Sussex home, yet she won't be able to install them before the subsidies are slashed next month as she is still waiting for planning permission. "It's an absolute panic," Lisle said. "I'm chucking thousands of pounds of my savings away unless I can somehow get it done before the deadline, because it isn't worth doing on the lower tariff."  Customers aren't the only ones up in arms. The solar industry has been in revolt since the Department of Energy and Climate Change said it would reduce the rate paid to householders by more than half, from 43p per kilowatt hour to 21p, for new installations.  The change will come into effect on December 12 - just six weeks after the announcement and before the government's consultation on the topic closes on December 23.  The department claims it is reacting to an unexpected boom in solar panel installations, driven by falling prices and the lure of double-digit returns on offer through the feed-in tariff.  More than 100,000 families across Britain have solar panels on their roofs. The take-up accelerated 300% in the three months to October, according to government figures, eating into the ?867m subsidy pot.  Greg Barker, the energy minister, said: "The key thing is that I'm not closing the scheme, I'm reducing the tariff to a reasonable level. We suddenly had this bubble and huge growth in demand, and it's neither sustainable nor right that people should get these kinds of returns from a scheme funded by taxpayers."  The solar industry sees it differently.  although cuts to the tariff had been expected, the December deadline came as a shock. Solar firms warn that 25,000 jobs could be lost in a matter of months.  The CBI, the business lobby group, described it last week as "the latest in a string of government own goals".  Barker's department faces at least three separate legal actions. Solar Century, a panel installer, is leading a group comprising ardenham Energy, Encraft and Second Nature Partnership, which is seeking a judicial review of his decision. Friends of the Earth, the environmental charity, and Home Sun, another panel installer, are doing the same.  Solar Century's case rests on the argument that December's deadline is illegal because it pre-judges the outcome of the government's consult 