How it Works
See an example of live monitoring here.
PGE E1 Rate Tariff: This is the most popular residential billing tariff. The more electricity you use, the more it costs.
PGE EV Rate Tariff: This is the most popular residential billing tariff for customers that have an Electric Vehicle. It has Time Of Use (TOU) characteristics, meaning you are charged depending on the time of your consumption.
Transition from non-solar billing to solar billing:
This graphs shows pre-solar costs on top (the Tier rate costs have risen since this graph was generated).
The bottom portion of the graph indicates how a post solar Time of Use rate works well for customers. This is a residential rate, but the principle is the same for residential or commercial customers. The PGE costs are highest during the afternoon hours in the summer (May 1 to Oct 31st) period. Solar PV generates the highest kWh output during this same period. PGE credits solar customers the rate in effect at the time the solar energy is being sent to the grid. Therefore one doesn’t need to offset 100% of their electric usage to cover 100% of their bill. For example; if you have an electric car, and your solar system generates 10kWh in the afternoon between 2pm and 9pm, you’ll be CREDITED $3.60 worth of electricity. Over each day of your billing year, you’ll be able to “cash in” those credits. In this case, if you were to use 10kWh to charge your Electric Car, that same evening, you’ll only use $1.00 of those credits; and you’ll have $2.60 remaining in credits for use when your solar system is not operating or not meeting the needs of your home. See the annual “True Up” statement below.
Annual True Up Statement
The day your solar system is approved by PGE you will not have an electric bill payable to PGE for one year. Below is the annual billing from Mark’s home, his solar system offset about 65% of his electric usage, but 100% of his bill.
We’ll focus on sizing your solar system:
1. “GoSimpleSolar Max Solar PV System”: Maximize the PGE credits by minimizing or eliminating your electric bill with a larger PV system design: This will be the largest up front investment achieving the highest long term financial returns.
2. “GoSimpleSolar Optimized Solar PV System”: Design a solar PV system to have lowest Net/Net cost; smallest solar system size results in continuing to pay the lowest Tier electricity costs to PGE post solar.
3. “GoSimpleSolar Hybrid PV System”: After an initial design is completed and budget and long term goals are discussed, we’ll mutually design a PV system size that takes advantage of the rewards offered by both the “Max” and “Optimized” systems described above.
Solar kWh Production Monitoring of Your Solar PV System: Options
This is Mark’s inverter display in his garage. At this moment the inverter is operating in “Standalone” mode. This means that the utility grid is down, and his inverter is generating back up power, also know as the “Secure Power Supply”. The current back up power system is powering his radio (67 watts). This back up power feature is exclusive to SMA Inverters. (http://www.gosimplesolar.com/sma-inverters)
Our electrician can wire this back up power system into a transfer switch that will allow you to power what you like, up to 1500 watts, sunlight permitting. Keeping that food cold during a power outage? Absolutely!
In standard mode, the inverter display will indicate current power, daily kWh produced, and total kWh produced. Mark’s inverter indicates .015 megawatts produced. Mark just upgraded to a this new inverter because of the great advantages that the Secure Power Supply mode offers.
Web Based Monitoring for SMA Inverters
This is how Mark’s Web Based Monitoring appears online: This monitoring is available on computers and there is a smartphone app as well. This screen capture is from February 24th of 2014. The “Total Yield” indicates that Mark selected to view last years production data for January in that data block.
Combined Electric Consumption (electric usage) and Solar Production Monitoring, via PGE.com
Below is a screen capture from PGE.com > My Usage Tab
The 0 line indicates total energy consumption (above the line) or generation from the solar system (below the line) at the home for the selected day.
Mark’s electric car was being trickle charged from midnight (during the lowest cost hours) and his solar PV system started to generate power BEFORE the sun rose above the horizon (direct sunlight not required).
As the sun rose, the solar PV system began to generate more power than the home was using, providing multiple kWh credits at the lower tier cost hours (See chart above).
This is exactly why solar is such an excellent investment: Electricity rates will not likely decrease (they rarely have, and never for the long term) and the solar credits are protected by law for the next 22 years.
Comparison of the chart above and the chart below is a great way to see the performance of your solar PV system. You can watch the saving being generated!
Immediate Consumption and Production Monitoring
The only way to see immediate feedback (other than installing a home energy monitor) is to read your electric meter. The below photo indicates a 3.85 kilowatt per hour feed BACK to PGE. There are arrows to indicate which way the power is going. “Received” on the display means PGE is receiving your solar energy (and selling it to your neighbors). “Delivered” means PGE is providing the home’s power. The meter total reading of 99954 is BELOW zero for total use for the “True Up” year. Depending on solar PV system size, the number will rise above zero but as in the case above, in the “True Up” statement from PGE, 1128 kWh were used by Mark from PGE, but they didn’t cost him anything.