I don’t need to ask grok.

Here are high-ball numbers for going off the grid; 2000 sf house in California:

- 30 panels ~ 10kw: $20K

- batteries ~ 10kwh: $8K.

- permits + labor: $20K (California...)

- 100+kwh EV with v2h bidirectional charging: $50K

- comparable ICE car (offset): -$40K

- heat pump water heater $1.5K

- heat pump furnace: $15K

- induction range: $2K

That adds to: $76.5K. Typical PG&E bills are $500-1000 per month. Budget $200 / month for gas. (Again, California prices.). That’s 63-110 months till break even, which is less than the expected lifetime of the panels + battery.

For another $10-20K, you can add propane backup, but I assume extended storms are rare enough to just charge the car and drive the electrons home a few times a year. A fireplace is about $5k installed.

Not going full off-grid is cheaper. So is scaling up to beyond one house.

> That’s 63-110 months till break even, which is less than the expected lifetime of the panels + battery.

You might want to check these, they are way off. You’ll get double these times at least. Not sure why you need the EV plus separate batteries too?

Grid scale power is being discussed here, not your house project (which is totally great)

LLMs should not be used as a reliable source of numbers for research like that. You keep saying how obvious this is and trivial to research. Maybe just post a quality research link instead in that case?

I am suggesting it as a way to do a back of the envelope calculation that can be thoroughly checked manually. It's very easy to check the numbers yourself.

From o1 pro with deep research

# Comparison of Power Generation Options

## Upfront Capital Cost - *Nuclear*: Very high (£4,000-6,000/kW), with 10+ year construction time - *Natural Gas (CCGT)*: Low to moderate (£500-1,000/kW), with 2-3 year construction time - *Wind + Battery*: Moderate for turbines (£1,000-1,500/kW) plus substantial battery costs - *Solar + Battery*: Moderate for panels (£800-1,200/kW) plus large battery costs, especially for winter

## Plant Lifespan - *Nuclear*: Typically 60 years, with possible extensions; 2+ builds over 100 years - *Natural Gas*: 25-30 years; requires 3-4 rebuilds over 100 years - *Wind + Battery*: 25 years for turbines, 10-15 years for batteries; multiple replacements needed - *Solar + Battery*: 25-30 years for panels (with declining output), 10-15 years for batteries

## Fuel & Operating Costs - *Nuclear*: Low fuel cost, high operating cost (staffing, maintenance, safety) - *Natural Gas*: Major cost is fuel (price volatility), plus potential carbon costs - *Wind + Battery*: No fuel cost, moderate turbine O&M, plus battery replacement costs - *Solar + Battery*: No fuel cost, low panel O&M, plus battery replacement costs

## Levelized Cost (No subsidies) - *Nuclear*: £90-120/MWh - *Natural Gas*: £50-60/MWh (without carbon cost), £100+/MWh with high carbon prices - *Wind + Battery*: Base wind £40-50/MWh, potentially exceeding £100-150/MWh with storage for 90% CF - *Solar + Battery*: Base solar £40-50/MWh, potentially exceeding £150-200/MWh with storage

## Reliability / Capacity Factor - *Nuclear*: ~90% capacity factor, suited for baseload - *Natural Gas*: 80-90% if run as baseload, highly flexible - *Wind + Battery*: 35-50% raw CF for wind alone, requires battery + overbuild for 90% CF - *Solar + Battery*: 10-15% raw CF in UK, requires massive overbuild and storage for 90% CF

## Key Advantages - *Nuclear*: High-capacity 24/7 baseload, low CO₂, stable long-term output - *Natural Gas*: Low upfront capital, flexible/dispatchable, mature technology - *Wind + Battery*: Carbon-free, potentially low marginal wind cost, lower price volatility - *Solar + Battery*: Carbon-free, low operating costs, suitable for distributed generation

## Key Drawbacks - *Nuclear*: Expensive upfront, complex construction, decommissioning burden - *Natural Gas*: Volatile fuel costs, CO₂ emissions unless carbon capture added - *Wind + Battery*: High cost for baseload reliability, weather-dependent, multiple battery replacements - *Solar + Battery*: Very high overbuild and storage needs for 90% CF, seasonal variation