One of the most common misconceptions, when powered by the Sun, is that you no longer need to be concerned about consumption. Now all the power is free! Nothing could be further from the truth.
The most efficient use of electricity, whether you own solar or not, considers the time-of-use cost of that electricity. Utilities charge more during periods of high demand when they need to bring on more expensive generation to meet these needs. Rates are much lower when solar electricity is being produced midday or late at night when consumption is lower.
For 18 to 20 hours each day, it is likely that your solar array will not be generating enough electricity to meet your property’s requirements, During these periods, needed electricity will either be purchased from the utility grid or drawn from battery storage.
For solar owners, consuming more electricity while the sun is shining makes the most economic sense. Discretionary consumption by the washer, dryer, dishwasher, vacuum cleaner, hairdryer, pool pump and car charger should be considered during this time.
The next best time would be during off-peak times as defined by your utility. These differ by both the season, utility and plan. Although we may not be able to select our utility or avoid seasons, generally numerous utility electric plans are available to both solar and non-solar owners.
Once utility electricity consumption patterns are established by a property owner, the most cost-effective plan can be identified and selected. Generally, it is the unavoidable major consumption like air conditioning or the electric range at suppertime that determine the plan.
Some on-peak consumption-reducing practices do exist, but consumers may find them too burdensome to adopt. These include pre-cooling the property a few degrees before on-peak power begins, eating later or accepting a warmer property for a few hours.
Our utility will soon be adjusting to an on-peak power time of 4 pm to 7 pm on weekdays. As empty-nesters, our strategy will be to go to happy hour a couple of days a week, keep the house a few degrees warmer while we are gone, and avoid cooking!
Property owners with solar will have the excess electricity generated by their system during the day flow back onto the grid or be used to charge batteries. Electricity flowing back onto the utility grid will be credited to their account at a fixed price per kWh, close to that charged for off-peak power.
Excess electricity stored in batteries is generally for one of three purposes. The first, is for peak power shaving where stored electricity is used by the property, instead of expensive utility power, during peak pricing.
The second use of batteries is to provide backup power to the property’s critical circuits, fridge, freezer, lights, phone charger and AC, if there is a grid failure. The third use is to completely replace utility consumption with electricity stored in batteries for all electricity needs not met by solar.
In the case of this third option, batteries would be charged with enough power by excess solar electricity each day as would be needed each night. In this way, a property would be very much “off the grid” requiring no utility power if well designed. This may sound like the perfect solution, albeit an expensive one!
Considering investing in high-efficiency HVAC, Energy Star appliances, variable speed pool pump, upgraded insulation, new windows, or added shades. All of these can contribute to reducing electricity consumption such that the required solar system can be smaller, less battery storage capacity required or reduced on-peak electricity purchases made.
Power monitoring systems are an inexpensive way to receive alerts if consumption is abnormal, with a fridge door left open or electric range left on, further reducing consumption and costs.
Solar, storage, efficient and timely consumption, while selecting with right utility plan will all lead to the nirvana of the lowest possible electrical expense.