Solar Power Now Worth up to Triple the Cost of Grid Power in CO

This is big news for photovoltaic solar customers in Colorado.

I first proposed this in 2007.  Xcel then tried Smart Grid City which they bungled.

Xcel is finally letting us benefit from the advantages of:

"Net Metering Time of Use (TOU)

COSEIA and other solar parties scored a win with the agreement that  extra energy generated by solar systems in a given month can be rolled over as a monetary credit that recognizes the value of the energy at the time it was generated. The credit will be used to offset the bill for consumption the next month and can continually roll over. Those who have elected to cash out extra production will still have that option. "

(From a COSEIA email announcement of the settlement)

Time Periods:

On Peak:       2 PM through 6 PM (weekday, non-holiday)

Off Peak:       9 PM through 9 AM

Shoulder:      All Other Hours

Price per kilowatt-hour (kwh): 

                                Summer                     Winter

On Peak:                  $0.13814                   $0.08880

Shoulder:                 $0.08420                   $0.05413

Off Peak:                  $0.04440                   $0.04440

For example, if your PV system generates 10 kwh between 2 pm and 6 pm, Xcel must give you a credit of $1.38.

But if you can use the same 10 kwh during off peak hours, it will only cost you $0.44.

Some of the takeaways:

1.  Solar systems will earn more money if they face to the southwest instead of due south.

2.  Homes in Colorado can now benefit from smart timers and products like the Tesla Powerwall.

3.  The demand peak for power occurs at 4pm, which doesn't align with peak solar production. Battery storage is the key to solving this problem, hence the Gigafactory and V2G.

Note that there are a bunch of fees and charges on your utility bill that make it difficult to see your actual cost per kwh.  This issue killed TOU rates the first and second time around.

What Ever Happened to Off-Peak Electric Rates?

In the 1970's, PSCO introduced off peak electric rates, which were designed to flatten their demand profile. At the time, a kwh used between 10pm and 6am was priced at less than a third of the cost of an on-peak kwh. If utilities can just tweak their customers usage habits thru rate schedules, they can really drop their capital costs. That is, they won't have to build that new power plant just to cover three week long spikes in demand.

Over the years, the PUC added many "cost adjustments" to the electric bill, which watered down the off-peak savings to be had. Eventually, all customers lost interest in the whole program and it was cancelled. These cost adjustments are multiplied by the kwh usage, and now account for around 66% of a residential electric bill. It didn't matter if all the usage was off-peak, these adjustments were still there in full. So, in 1980 if you were saving 2/3 of your bill with off-peak rates, by 2008, your savings would be 2/3 of the remaining 34%, or only 22%.