It could start by imposing a windfall tax on energy companies profits, coupled with price controls to ensure the cost of such a tax is not passed onto consumers. In fact why not impose a windfall tax for the next 5-10 years to guarantee these firms stump up the cash for all the investment needed?
What? We fix prices low then tax whatever profits are left more heavily and this will make people invest more?
Sorry, but are these people inhabiting the same planet as the rest of us?