Solar energy may have caused California’s wildfires

As an elected politcian I wasn’t surprised to find that my council had no snow shifting equipment “snow will be a thing of the past” – we didn’t need it, so why spend money storing it? We’d been told by experts and they know what they’re talking about. My political training meant I knew that I had a duty to question experts, but not to challenge them.

Then we got hit by snow, lots of snow. Ringing round it was clear every other muncipal body had done the same “we sold ours off because we were told we didn’t need it”. Even the schools had sold theirs off. I decided at that point that I’d be more cynical about climate predictions while spedning public money buying new snow shifting equipment at inflated prices.

Whenever I see a clear statement about climate change and its effects I now look at the background. That made me look at the research on the wildfires in Ca. I can’t find the paper, but there was an excellent one by meterologists about two years ago. (I like meterologists – they like science and aren’t interested in politics). In essence; there’s IS an alteration on the climate in that part of California. All that agriculture uses water and not all of it ends up, or stays in the ground. That causes an increase in humidity over quite an area and that encourages brush and other growth to a greater extent than would otherwise occur. That extra growth dries out when the dry season hits and there’s a greater volume of firewood looking for an obliging spark than there would be if there wasn’t the agriculture. So, there is more man-made bushfire fuel and it’s down to agriculture.

All the main reports say there are fewer widlfires – https://www.ocregister.com/2017/09/14/you-may-not-believe-it-but-the-number-of-california-wildfires-has-been-going-down/ There are more technical versions of this report available but this is easier to read.

One other interesting thing those meteorologists did say in that report, was that in terms of claims of “increasing temperatures” that the increased volume of snow fall in the mountains meant that those claims of climate change temp rises were “not compatible” with what had been recorded and observed. “Not compatible” is the meteorologist’s equivalent of “baloney”.

I happens that this week I reviewed a conference paper on grid stability and how it can be improved using the careful placement of static synchronous series compensator (SSSC) in a simulation of a multi-bus and multi-source grid. The impact of a three-phase fault (disconnection) was determined, comparing the presence or absence of an SSSC placed optimally.

The placement of, for example, battery storage, an inverter and phase stabilization unit greatly improves the likelihood that the voltage can be maintained and the negative impacts on equipment of a mis-timed movement of a voltage regulator core (the moving core type in common use for decades) mitigated as the system tries to adapt to a new load condition. That new condition is typically caused by a disconnection of a load (fuse blows or very large motor is turned off) or equipment failure (transformer pops).

The idea is to control the voltage and current in the whole system to prevent exactly what cause the South Australia blackout: sudden drops in local voltage and consequent over-demand on interlinks.

When there is no disconnection (blackout) there is momentary brownout or down-spike conditions, frequently all three. The system simulated included 14 generators, 14 transformers, 51 transmission lines and 20 load buses.

Such SSSC devices require communication links to grid points so it can make optimal management decisions within portions of a cycle. Poor decisions or absent any modern management system at all (check out Germany’s which has a human finger on the button all the time) means there are inevitable and negative consequences for individual system components.

The explosion of a single transformer on a pole can happen when the local load was low, the system voltage dropped and the local load suddenly increased. A sudden increase can happen most easily when another transformer disconnects or if there is a sudden reversal of flow direction through an interlink. It is perhaps best to consider this latter case when solar input drops rapidly at the very lime local consumption rises. Flow reverses all over the grid.

Voltage stabilizers on the grid have to rapidly switch from a step down to a step up condition, while suddenly the power is coming “from the other direction”. Homes that were sources become consumers in a highly complex pattern across the grid. The voltage settling time can take 10-12 seconds for each disturbance. Multiple ripples shooting through a system with multiple regulators each trying to sense and correct the local line voltage requires the production and absorption of reactive power. It is logical, as often read here, that spinning reserve has to be available to cover sudden drops in supply. It must also cover reactive power demand.

Consider how many sources of power there are with and without rooftop solar. As the sun goes down they are shaded and over-clouded in a system-wide predictable manner, but not in a fine scale. Shunting power around on a collapsing system (in terms of power generation points) becomes taxing. In the morning when the reverse applies, think of it as 10,000 lights going off randomly and suddenly being converted into little battery chargers, and your task is to disconnect or ramp down a dozen sources placed hither and yon across the grid. Now, maintain the correct voltage at each of 10,000 points.

Do this with each light bulb changing from a resistive demand to an inductive load. Oh wait, a random distribution of them making a random change from one to the other. Good luck.

When the reactive power demand is high, voltage is raised to push additional current through the inductance of the lines themselves. If the demand suddenly drops, voltage can spike on one or more transformers causing a lot of local heating. Do this 500 times an hour and see what happens.

The transformers most likely to blow up will be where voltage spikes have been common and the large scale regulation is further away from reactive power capacity and where phase correction capability is at its lowest. There is a general rule that “reactive power doesn’t travel far”. California is big.

One reason for widespread blackouts is reactive power that went out of control. Blackouts are bad for business, so vendors allow things “to heat up a bit” here and there. Yeah, well, no, fine, there are inevitable consequences for bending the laws of physics.

On a hot day the transformer may already be extra hot from channelling PV power to the grid in one direction. Then the changeover chaos begins. Then the regulators have their fun on autopilot (no human could do it) and the equipment takes a beating in an attempt to keep everything stable.

Does anyone remember the Aug 10 1996 blackout on the West Coast? That was a voltage collapse. In some cases a blackout can be prevented by temporarily overloading transformers (heh heh). If it is already hot after a long days work, it goes too far. The system doesn’t sense the temperature of the oil in every little transformer, it senses voltages, phase and current.

The August 14 2003 blackout in NE USA and Canada was not caused by a voltage collapse, but directly by inadequate reactive power and inadequate control over it.

And add to all that, sometimes equipment just fails. If you are in charge of maintaining a secure supply and it all goes wrong, and it burns down half a State, you (and those that survive) can always declare bankruptcy and start again. Rinse, repeat.

Conditions were not unusually dry at the time of the Thomas or Camp fires. Historically, California has had recurring, extended severe droughts. The record of that history is well-known and easy to access. California has become neither hotter nor drier in this century.