John,
What you are describing is your personal needs and situation, which are clearly quite unusual, and also not suited to a solution using solar. From that one data point, you then extrapolate to “solar doesn’t make sense for anyone”. That’s some faulty logic.
As for the motel, relying exclusively on electric heat with no backup generator in a rural village with known power problems is clearly stupid. Do keep in mind that most of us aren’t powering motels with electric heat, so that sort of calculation won’t be relevant.
As for the recent problems in Texas, it has been clearly shown that renewables were not the cause, despite a concerted effort to pin the blame there. Renewables aren’t perfect, they aren’t the answer to every problem or use case, but the technology is rapidly evolving and improving, and it makes sense for many people, even if not for you.
Tom
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On Mar 23, 2021, at 12:22 AM, NeonJohn <jgd@...> wrote:
?
On 3/22/21 10:40 PM, Tom Rymes wrote:
On Mar 22, 2021, at 9:13 PM, NeonJohn <jgd@...> wrote:
On 3/22/21 5:46 PM, Barton Fisher wrote:
I've actually thought of doing this. Maybe incorporate into the charging / home solar system.
I have a 10kVA auto start/transfer propane whole house generator and 2 months' worth of propane. i installed the system which cost $5,000. Seems a lot more easy and sensible than wasting all that money on marginally functional solar. Solar is irrelevant for me anyway because my house is fully under a canopy of trees in the forest.
I find your comment interesting, but the only part that makes sense is the part where solar make little sense for you because of tree cover. In that case, the generator is the better choice.
For most, or at least many, people, though, it would make much more sense to put that $5,000 towards a solar system with battery backup, providing much of the benefit of your generator, but also with the added benefit of cost savings every month. Sure, it makes more sense in Phoenix than in Halifax, but solar seems like a better choice to me in most cases.
let's do an analysis for using a C-car battery for emergency power. There are 220 amp-hours * 50 volts (6.25 volts * 8) = 11k kWh.
Before I installed the generator, I had a 1500 watt 48 volt UPS. To use nuclear plant terms, I divided my house into Vital Bus (refrigeration, one CFL in each room and computer equipment) and Balance of Plant, unimportant things that lost power when the utility failed. I used 220 AH Trojan 6 volt wet cells.
The load on the UPS with the refrigeration running (modern refrigeration is designed to run about 90% of the time as an energy saving measure), a CFL on only in the occupied rooms and my computer equipment totaled about 750 watts. So I had 11 kwh / 0.750 watts = about 15 hours of emergency power.
I researched solar on NREL, contemplating cutting the trees shading my cabin. At my latitude (SE TN) It would have taken over $20,000 in solar panels to replace the power used when the sun didn't shine each day in the summer-time. In the winter, solar would have been hopeless, as we're under almost constant overcast.
With this setup I could NOT run my AC, a vital accessory in Green Cove. This area is knows as America's Little Rain Forest. The humidity remains near 100% most of the summer and the temperature averages around 85 degrees in the daytime but has reached 100 deg. AC is simply not an option.
To charge the batteries as fast as possible, I bought a cheap 10kVA generator and redesigned it with a PM field and rewound the stator to produce 60 volts peak at 100 amps. My very best friend (who died last Thanksgiving) owned Jerry's Electric Motor Service shop and I had the run of the place.
I controlled output voltage by varying the engine speed using a medium sized RC model servo and a board that I designed and programmed. It did a full 3 stage charge profile.
Unlike the crap batteries places like Sam's sells and many C-car owners use because of the price, the Trojans would reach approximately 80% of full charge while still in the bulk phase (100 amp charge rate). They would reach the float stage in about 2.5 hours. In contrast, the Sam's and similar ilk consumer batteries fell out of bulk (constant current) and moved to absorption ( constant voltage) at about 40% of full charge. This because of the high internal resistance.
As soon as I could afford them, I added a second string of Trojans in parallel with the first set to extend my capacity beyond 24 hours.
The second revision of my board measured battery voltage and auto-cranked the charger when the batteries were about 80% depleted.
Since the primary power feed to our village is 25 miles long up a rough mountain right of way, outages are typically multi-day affairs. After 2 summers with no AC during outages, I bought the 10kVA auto-start whole house generator. When the power goes out, the generator computer waits 10 seconds to make sure it's an outage and not a switching transient, cranks the engine, lets it warm for 5 second and throws the transfer switch.
The old system still exists, the Trojans replaced with a 600 AH 48 volt fork lift battery. It keeps the vital bus up during the 15 second transfer and keeps the bus up if the generator fails to start, something that happened once when the solenoid choke stuck shut.
My "cordless battery charger" cost me about a $grand and the Generac about $5k, another $5k had I not done the installation. So for about $6k plus the cost of the batteries, I have a 100% available, highly reliable emergency power system that will carry me up to 2 months of the power being down.
In the infamous Blizzard of '93, 2.5 ft of snow fell overnight in April. This is a trout fishing destination and the season was in full swing. The all-electric motel (about 75 rooms) was sold out. The power was off for 9 days and the sole road closed for 12 while they removed over 200 trees from across the access road.
The motel owner was too cheap to provide alternative heat such as propane so everyone froze. The people who built the motel built a large apartment with a fireplace to live in. Several men went out and (illegally) cut trees from Forest Service land and everyone from the motel crowded into that one room with the fireplace. Meanwhile everything here was normal. I allowed people to come here a few at a time to warm up and shower if desired.
A National Guard Helo dropped in a couple of pallets of MREs, mostly eaten cold because the packaged chemical warmer was designed for a desert environment. I'm not a prepper but I keep a month's supply of food on hand for the two of us. Several times I cooked them hot stew, chili and so on, on an electric range.
I would have been in a similarly excellent position had I been in Texas recently. Texas is too independent to wheel power (wheeling is moving excess capacity to areas undergoing a shortfall) through the state so only two tiny interties (about 1GVA) exist, one on either side of the state. This blizzard demonstrated yet again the utter folly of relying on so-called "renewables" for base load. Texas almost lost the state grid about 15 years ago when the wind suddenly stopped blowing for a few hours. They saved the state only by virtue of having maintained many of their gas turbines and gas fired steam plants in cold standby (ready to start in seconds to hours) until the wind started blowing again. Many of those plants have since been demolished which is why the blizzard shut down the state.
John
