Can anyone comment on the claim that private solar power generation affects the stability of the grid? What kinds of infrastructure changes would be needed to properly support power generation in private homes?
There is a disconnect between market forces in energy production right now.
Right now, short-term grid frequency and voltage stability (periods of seconds to a few min) is regulated automatically by the governor response of the various generators on the grid. These governors bid in advance to set their proportional gain for frequency stability. Basically, they promise to autonomously raise or lower their throttle in the future based on the observed grid frequency and voltage, and get paid later when they make good on their promise. Long-term stability (periods of 15 min or so) are regulated with market action in the spot market for power. Very long term stability is regulated by markets that clear 24 hours in advance of their estimated delivery.
However, some energy producers effectively have flat rate contracts that don't participate directly in grid stability. Wind and nuclear will negotiate a fixed power-purchase agreement (typical prices are about 50 USD/MW-hr or so in the US) that will be fixed for years at a time. Likewise, residential solar customers sell back their power under the same, basically fixed rate schedule that they use to buy power.
So, as the penetration of fixed-rate power increases into the market, the pricing volatility continues to increase as well. There are technologies that can help. In fact, it is trivially easy to get a grid-tied inverter to be sensitive to grid changes with controls that model virtual inertia, impedance, throttle, and so on. This is part of what I do as a controls engineer. The difficulty isn't in implementing such controls, it is in adjusting the markets such that all of the existing players are comfortable with the result.
Witness this in Hawaii - the retail price of power is so high that it makes obvious good sense to install your own generation. But instead of adjusting the rates to reflect the new availability of supply, the incumbent utility seeks to raise barriers to competition instead.
...the retail price of power is so high that it makes obvious good sense to install your own generation. But instead of adjusting the rates to reflect the new availability of supply, the incumbent utility seeks to raise barriers to competition instead.
Incumbents elsewhere might find themselves in similar situations. If they react the same way, enough localized generation and storage will appear that they will find their business unworkable at any rate level.
The grid is built on the assumption of a few central points producing almost all electricity. This creates a grid focused on distributing away from those points. A more distributed and fluctuating producer situation will need more distribution between different branches of the network than the current infrastructure can handle. It will also require extra power generation that can be started on demand when the power production is lower (due to clouds, night, etc). This requires a lot of extra capacity that will get very low average utilization and therefore be very expensive due to being expensive to set up.
Well for one, whenever a power-line goes dead... the Solar panels need to shut off so that the workers can safely replace the powerline.
There's nothing quite like "Oh, some home in this neighborhood is still powering this powerline, despite the fact that we've shut off all the other power sources". That's quite the real "shocker" to the poor worker.
I suspect if this weren't the case we would already have heard about all the burned houses. There's nothing the media likes to hype more than something scary and new. Of course, this is why engineers and electricians are licensed.
