I agree, Solarcity market will only grow stronger with mass market batteries.Despite abundant sunshine, Georgia has little sunshine. Why has SolarCity not entered this market. Up until about 6 months ago, it was illegal for solar installers to lease, unless they happened to be a utility. But our state government has passed legislation to remove that barrier to entry. But SolarCity faces another barrier: power is cheep in Georgia. However, Tesla Energy products may change the economics and open a way for SolarCity to turn a profit in Georgia.I have been helping a condo community sort through options for installing EV chargers. In the process, we have learned more about the commercial rate plan this HOA has. Roughly, this plan prices energy at 9c/kWh and monthly peak demand at $20/kW. SolarCity may not be able to compete with the energy price offering a solar system without storage. While a solar only system can reduce peak energy use when the sun shines brightly and AC hums, but the AC demand at and after sunset as well as monthly variability in solar output can lead to very little relief from demand charges. So without storage, while at 25 kW system could reduce demand in certain hours by 25 kW, the monthly peak demand might only amount to a few kW in hot months. But suppose we pair 25 kW PV with a Powerpack at 100 kWh and 25 kW sustained. The Powerpack along may not be sufficient to reduce peak demand by 25 kW, while it can certainly provide that much power for 4 hours at a time. So if peak loads are sustained longer than 4 hours at anytime in the month, a Powerpack alone cannot reliably cut peak demand by 25 kW , maybe 15 to 20 kW. But suppose the solar and battery can work together synergistically to reduce peak demand by a month average of 30 kW, where solar alone provides upto 5 kW and Powerpack alone upto 20 kW. The extra 5 kW or more demand reduction is the benefit of synergy, and at $20/kW.So let's figure out what this is worth on an average monthly basis.Solar energery. 25 kW × 120 h = 3000 kWh @ $0.09/kWh = $270Solar peak demand reduction. 5 kW @ $20/kW = $100.Powerpack alone peak demand reduction. 20 kW @ $20/kW = $400.Synergistic peak demand reduction. 5 kW @ $20/kW = $100. Thus a PV only system creates a benefit valued at $370 per month or 12.3 c/kWh. Over the course of 20 years this is worth $88,800 or $3.55/W. However, the combined PV + Powerpack system generates a benefit worth $870 per month or 29 c/kWh. Over 20 years the is worth $208,800. Since the Powerpack will need to get replaced in 10 to 15 years, but in that time the cost could drop from $25,000 to $15,00, even $10,000. So let's assume over 20 years time s40,000 will be spent on storage. We net this from the gross benefit to get a net benefit of $168,800 or $6.75/W solar.So we see the potential of storage to increase the benefit per Watt from $3.55 to $6.75, a gain of $3.20. Surely at a benefit of $6.75 there is plenty of opportunity for both customer and SolarCity to profit handsomely. Indeed, both could profit to the tune of $2/W or $50,000 each.Not only does this example illustrate the potential for solar+battery to make economic sense. It also underscores how important the cost of grid capacity is. In most residential rate plans, there is just a rate for energy. This rate includes the cost of grid capacity. But in a plan with demand charges a specific price is put on grid capacity. PV only systems are not well suited to create reductions in required grid capacity and most rate plans do not properly reward owners of these systems for these modest reductions. But rate plans with demand charges do put a specific price on capacity demanded, and solar systems with storage are best suited to optimize rewards for reduced capacity requirements. We make a big mistake in thinking about renewable energy to focus only on energy costs and not recognize capacity costs. In this example, the combined cost that was offset was $870/month or 29 c/kWh, but the energy benefit was only $270/month or 9 c/kWh. So about 2/3 of the benefit was obtained by reducing capacity requirements. Incidentally, Georgia Power does have two residential rate plans with demand charges built into them, but most residential customers choose other plans without demand charges. I'll leave it to the analysts to workout which combination of PV and battery will yield the best return for each specific utility rate plan, but where a specific price is put on capacity, batteries have an opportunity to capture that value. Batteries may well expand SolarCity's addressable market, even into Georgia.
SolarCity Now
again, I see 7Gw of production today. Please verify if necessary.
