Though not one for use of tweets or blogs or other forms of social media, I find it necessary sometimes to unclog the mind with a stream-of-conscious offloading of information. Hence, this article is not a singular theme but rather a series of information I learned at recent power quality standards meetings that seemed worthy to share.
Electric utilities have deployed countless smart meters around the country, and the consumer generally pays the cost. So the user is paying the utility to provide it with the capability to charge time-of-use rates for electricity and even real-time pricing rates. This is especially noteworthy during the hot summer months, such as July, when New York state hit a record consumption of nearly 40,000 megawatts (MW) and peak pricing of $500 per megawatt-hour, which is nearly 10 times the average cost.
Smart meters were touted as having power quality capabilities that will improve the grid’s reliability. Attendees at the power quality meeting noted that few, if any, of the marketed capabilities are being used, either because meters were bought without such capabilities because they were deemed too pricey, or communicating, downloading and processing the power quality data was not worth the cost. The meter telling you that you have no electricity at your house during a blackout or interruption may help improve restoration time but will not prevent the loss of power.
Given the newness of the meters and future plans for them, some utilities intend to replace them with newer models with more capabilities in five years or so. Let’s see, my under-glass electromechanical wattmeter has lasted more than 30 years, and now the new one is only good for five? And who is paying, again?
The distribution of local renewable alternative-energy sources is part of the push to reduce dependency on oil and other “polluting” type energy sources. This, of course, is a worthy endeavor for future generations to have a better environment. However, some claims for improved reliability again have a ways to go. With the current interconnection scheme of distributed sources into the grid, the alternative-power source is supposed to trip offline when a voltage sag or interruption occurs. Therefore, the high energy consumption in the summer strains the grid, and something temporarily reduces the voltage. The distributed sources all trip off, leaving the already-strained utility generators with more power to supply, which is then likely to cascade into an interruption if it sustains much longer.
Power factor charges are included in some rate structures because the wattage consumed by the facility is significantly lower due to poor power factors of its loads. The utility must have the system capacity to provide the necessary larger volt-amperes. The reverse is true for generation by utilities with regard to power that may be supplied by alternative sources. When it is hot and the wind isn’t blowing and the clouds are obscuring the solar panels, the utility must still have the capacity to provide all of the power. Who pays for this reserve capacity that isn’t making money for the utility when it is sunny and/or the wind is blowing adequately?
Photovoltaic (PV) panels have come down significantly in price, considering incentives and rebates, but they still seem to be an option for the more affluent. One knowledgeable person in the field who has been involved with PV technology for more than 20 years finally decided to install 8 kilowatts of capacity on his roof, knowing that even after the rebates and other incentives, the return-on-investment of his $25,000 outlay will take many, many years to break even. Also, one must consider the amount of time that is needed before a solar panel has generated more energy than was used to produce it, the greenhouse gases generated in production, the rare earth metals used in manufacturing, and the hazardous waste provisions at end-of-life.
And since this is a power quality column, both PV panels and wind turbines use inverters to convert the generated voltage into a grid-frequency synchronized voltage. Inverters are nonlinear devices, which we all know generate harmonics and can develop harmonic resonances. They also can contribute to flicker problems resulting from the variable source of energy.
The future of electric supply and demand needs to progress with new technologies that make electricity a more reliable and efficient resource while reducing environmental impacts, but moving forward, energy producers and consumers should base decisions on what is really happening in the industry.