[URSpider94]

One problem that will surface is that the cost of our transmission infrastructure will have to be covered, one way or the other. Currently, with net metering, customers are able to arbitrage power at the retail price, while effectively making use of the grid for both pushing and pulling load. This would be like flying a round-trip from San Jose to Tokyo and back to SFO, and claiming that you only owe the airline for the Caltrain fare up the peninsula.

The other issue is that our current infrastructure isn't designed for peer-to-peer transmission, with neighborhoods pumping large amounts of power into the transmission lines during peak solar hours. Some areas of Hawaii have had to put a moratorium on installing rooftop solar to prevent potential damage to the branch circuits.

Long story short, it's not simply a matter of storage costs undercutting retail power costs, there are also maintenance costs for the grid that are invariant on demand, which will have to get paid one way or the other.

[driverdan]

I think you misunderstood something in this article. The only stored power that would be on the grid would be from the power companies themselves, not the end users. End users wouldn't resell the power, they'd use it themselves.

[ridgeguy]

The growth of distributed solar + storage (i.e., zillions of residences having 10kW arrays and 25kWhr storage) is accelerating. Projections I've seen suggest that this distributed storage (which doesn't belong to the power companies) will be far larger than utility-scale storage such as discussed in the article. This presents real challenges in how to control that distributed storage and pay its owners for storage-related grid services.

[bjelkeman-again]

Why can't it just be a feed-in tariff? And if the consumer can consume using the network they can produce, in the other direction. The cable runs both ways, no?

[ridgeguy]

It can be, but that doesn't capture the value a consumer with fast response, controllable generation/storage supplies to the grid. Compensating the consumer for power or storage they supply at a particular time is complicated.

Existing net metering pays a fixed rate for power supplied to the grid by, say, a solar-equipped residential grid customer.

But in fact, fast response power delivered to the grid when the grid managers call for it commands much higher prices in the dynamic electric power market. So does the ability to store power on demand (absorb power from the grid), when generation briefly exceeds supply.

So imagine a residential grid customer with local solar + storage that's controllable by the ISO (grid managers). Rather than net metering (a fixed feed-in tariff), the ISO should pay instantaneous market rate for power delivered, or absorbed by, the residential grid customer.

I think we'll soon converge on bidirectional power delivery/sink services that are controlled by either the ISO or perhaps by local smarts on the resident's grid-tie interface. That would engage the resident's system as a grid stability enhancement tool, and would bring more revenue to the resident than simple feed-in tariff schedules. One assumes the resident would participate by an opt-in choice in exchange for enhanced revenue.

[bjelkeman-again]

Thanks, very informative. The biggest challenge seem to be that the current people running both te grid and power companies are so conservative that they seem to be the biggest blocker against something line this being created.

[aharonovich]

IMO It only seems that way. They do their best to stay on top of all new technology, but as consumers are used to very high level of service (>99.99%) they can afford few risks if any.

[mark-r]

All the more reason for local storage. The closer to the end user that the power is stored, the less load on the transmission lines. If you store it at your own house, it never needs to hit the grid at all.

[URSpider94]

Yes, that's a good thing. However, imagine a world in which everyone has local storage and only needs power on the 10 days of the year when it's dark and rainy. So, let's say the total power draw per household drops to 100 kW per year (about $15 at California power rates), vs perhaps 10,000 kW per year today (about $1500). Meanwhile, the cost for maintaining the infrastructure changes very little -- crews still need to come out and trim trees away from the lines, pull fried squirrels off of transformers, re-string lines after a storm, etc. Assuming half of your current bill is spent on infrastructure, the utilities would need to recoup $750 or so per year from their customers to provide that $15 in power.