From Roy Harrison, Verwood, Dorset, UK
You report on home solar being vulnerable to hacks that could derail power grids. My solar installation poses little or no threat as its design limits its output to the grid so that, in the event of there being no demand for its electricity, it will detect this and reduce output appropriately(12 July, p 11).
I insisted on it having no internet connection via which the parameters controlling these behaviours could be interfered with. I did this because of the primitive nature of the security arrangements. If you know the password for such systems, you can not only read performance data, you can also change the parameters, possibly leading to destruction of the inverter or instability in the grid. This is a formula for ransom demands.
