The absolutely disgraceful way, over the last decade, that consumers have been treated by the energy companies and the government looks likely to deepen post-Brexit. Individuals will have less redress, losing the ability to report energy companies to the EU bureau of consumer affairs rather than the largely toothless UK ombudsman and there will be no change in the way energy companies are allowed to make a five percent return on capital... a crooked set-up that encourages them to increases costs and prices so they can justify ever increasing turnover and hence a bigger profit.
The complete incompetence of government bodies supposed to impose some restraint on these companies has managed to knock out many smaller energy companies whilst constraining tariffs in such a way that there is no encouragement for low energy users. Such is the depth and length of the rip-off of energy consumers that a radical attack on tariffs is needed to rebalance the current outrageous state of affairs. All standing charges need to be removed, companies allowed a single tariff with discounts for fixed direct debits (the idea that people should allow energy companies to vary their direct debits a modern absurdity that emphasizes the contempt in which consumers are held) and, to encourage miserly energy use, the first £20/month should be at a fixed rate that is half the price of the current rate. And, post Brexit, low energy use would be zero rated whilst higher users would pay twice the current 5 percent.
A further benefit of Brexit, zero tariffs and taxes on solar panel and air-source heat pump imports whilst at the same time smart meters would be configured to run backwards to credit the consumer directly with any excess energy produced in the summer/winter. No other incentives needed, well insulated houses using heat pumps would probably overall be self-sufficient in electricity and not need gas, payback on (now much cheaper) solar panel installation then being measured in years rather than decades.
Post Brexit, all this would go down well with the populace and redeem the dreadful way the government has allowed energy consumers to be treated. At the same time, phasing out council tax in favour of increasing taxes on business would then radically reform the fixed costs of living in the UK, freeing up cash to keep the general economy ticking over.