Tesla House Battery / Utility Scale Battery

The net is abuz about a battery announcement coming from Tesla on April 30. One post quoted a possible price for a 10kw house battery at $1.30/watt. Haven't seen a smart control system that would grid-tie this well to charge as the PV system had excess current available and discharge to the house when the PV system had insufficient energy, but it would seem this needs to be a part of the deal.

However the shake-out proceeds, the poor will be the very last to benefit, if at all.

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This is open to discussion. Do the "poor" benefit from my solar? I would say yes:

1) My excess kwh are daytime, times of load management of peak loads by the utility and service interruptions. I am adding capacity which will reduce the utility need for load management, which will result in less service interruptions and less need for the utility to buy expensive peak power, which should reduce rates for everyone.

2) My PV is adding efficiency to the grid. I doubt that my excess kwh even make it a mile down the road before they are used by other consumers. Line loss of such short distances is minimal, compared to 10-20% on grid supplied power. Increasing efficiency also translates to more kwh at reduced cost to the benefit of everyone.

3) My PV is a capital investment in long term power, paid by me privately, thus relieving the utility of need to add generating capacity at huge cost with cost recover through rate increases. Once again, reducing utility costs and more kwh to everyone without additional capital cost and rate increases.

4) This is nearly a ditto of (3). Distributed power means less need for long distance transmission lines, and avoidance of another large capital cost recovery by the utility through rate structure and rate increases. If distributed power is wisely planned, there also should be little need to add short distance transmission capacity which in any event is much less disruptive than long distance transmission lines.

5) Hard to conclude that those installing PV are really benefiting directly. Rather, they are benefiting generally as are other rate payers and the public. They may be receiving a reduction in current charges at the cost of a substantial capital investment and cost recovery which, in my case, is nearly 20 years into the future. And I am bearing the future risk rather than the utility and its rate paying customers. Many including me would conclude that residential PV is really more costly than grid electricity, unless the other non-reimbursed indirect costs of grid electricity are paid to the PV investor. But may main reason for investing in PV was because "it is the right thing to do, something which my utility is not doing."

6) I will package the social and environmental benefits in one bundle. Estimates are that these costs likely are in the range of at least equal to or more than the current charges for electricity. Everyone benefits with clean, safe, power and a healthier environment, reduced illnesses, etc.

PV, like most other innovations, is driven by the wealthy, the early adopters, those that set the future trends. Same with automobile, electronics, and the list goes on forever. In the long term costs drop to the great benefit of everyone; meanwhile some have also benefited hugely. PV is not unusual or an exception in this regard. It is capitalism and free enterprise at work. Let PV compete on a level playing field rather than continuing to give government sponsored and enforced monoply control to large utilities.

Lastly, most utilities are investor owned. Do you doubt for a moment that these investors are profiting at the expense of the poor from the current system?

I agree that utilities or utility scale batteries will be a major player. I also would not be surprised if there is more movement to off-grid with more affordable battery packs, more competition, even potentially less regulation.

Might a fit for the battery for those with PV, even with grid RE, be to supply electricity to the home/farm when solar is not producing or under producing and where full credit for excess kwh supplied to the grid is not compensated to the PV producer? For example, our general service electric on average is about 400 kwh/month, or about 13 kwh/day. Our PV roughly on average supplies 20% of that usage with 80% from the grid. Our heavy usage is during non-sun times. On average a 10 kwh battery, with direct use PV, would meet 100% of our general service home electric usage -- meaning now solar would be providing 100% of daily usage.

As to the remaining excess solar to grid, it would not take much load control to shift DHW heating from current timed service from the utility (between 11pm and 7am) to daytime periods when excess solar is being produced. On average that would be an additional 3 kwh/day. Similarly, during periods when we use electric supplemental heat in our lower level (Nov - Apr generally), rather than baseboard, we could use a ceramic electric storage unit to charge on excess solar and then provide the heat when needed. Electric heat from Nov - Apr averages 20-30 kwh/day. That still leaves May-Sept when there would be excess solar produced which I likely will not be able to capture, but on the other hand this is AC season and the utility may want the excess solar to meet demand for AC.

The point I am making is that PV with some home battery storage could substantially even out PV surges to the grid and provide a return to the PV homeowner that might not otherwise be available due to net metering restrictions, charges or unavailability, depending on the utility. Utility scale storage could offer the same benefits to the utility to even out PV supply, but there may be an advantage, cost or otherwise, to smaller scale storage as well.

Further as to home battery storage, might this be a market for the utility to lease the batteries to homeowners?

I see on Amazon 4 - 4ah 18650 li-ion batteries at $13.69, or $3.40 each. 2500 of these batteries would be 10 kwh of storage at a price of $8,500. A 10 kwh battery pack with charge/discharge control, and probably a higher quality battery, likely would cost more, but ballpark pricing could be in this range.

Not promoting li-ion, but the idea of house batteries seems to be very feasible, practical, and in the end competitive.

It will be sold to installers for $3,500 for 10kWh, and $3,000 for 7kWh. Deliveries will begin in late Summer.

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The controller technology could be as simple as a timer, if the battery is used for night charging at low utility rates and then supplying electricity to the home for the morning coffee and evening dinner, and maybe some AC during the day. Or with a sensor monitoring PV output and house demand, when PV exceeds demand, charge the battery. In my case, typical daily kwh usage is 10-15 kwh total (not including electric heat). A photocell sunlight sensor could switch charging on and off during the day from PV, and except for densely cloudy days, my system produces enough kwh to meet daytime demand and/or charge the battery and the battery would meet demand from sunset to sunrise.

Not to get bogged down on the details of the controller possibilities, the real big thing is an inexpensive battery that combined either with charging from low rate utility supply or PV, or both, real economies may be on the doorstep, including fully off grid for many more PV users.

Local utility rates will vary, individual motivations will vary, available incentives will vary, and state laws will vary. If an analysis is made on kwh usage and having a battery that can charge when PV is available or when the grid has excess capacity, then a much different picture of energy supply and cost starts to form, as well as a much different picture of environmental impact of energy usage. Imagine most houses having a 10kw battery and businesses larger kwh batteries, grid tied to draw from and possibly even supply to the grid - micro distributed power which would even out grid supply/demand, possibly eliminate or greatly reduce the need for peak generating capacity, and add a level of emergency energy security. Imagine greatly reduced carbon emissions, cleaner and healthier air, water and soil - an environment that sustains rather than depletes life.

I give great credit to people like Elon Musk and Tesla. People like him in various areas imagine a better world while most of us barely can get past a cup of morning coffee and the last installment of Survivor. We need more of and need to celebrate the great thinkers, great entrepreneurs, and great risk takers. Without those that came before we still would be wearing loin cloths and using a rock for a hammer.

As to the reality of the geek factor related to PV and battery storage, so what? My neighbor drives a big honker pickup truck ($40,000), one person in the vehicle, rarely hauls anything in the bed -- just because he can. Another neighbor has a 6000 sq ft home -- just because he can. Another neighbor is a bejeweled fashionista -- just because he can. Not one of these has any payback, let alone an economic payback. So what? Our lives are full of geek factors, culturally induced behaviors, and shaped by big bucks media advertising. PV has real value beyond the geek factor.