Power at Work: What will smart metering mean for your farm?

Monday, April 5, 2010

The opportunities for most farmers to shift their activities to take advantage of time-of-use pricing are limited. In fact, it may encourage greater use of self-contained standby generation systems

by RALPH WINFIELD

Most of you will already have a smart meter installed, or will have one shortly on your electrical service.

Personally, I have real difficulty with the term "Smart." My Webster's Dictionary and Thesaurus list the adjective "smart" as meaning: keen; quick; sharp; brisk; witty; spruce; well-dressed. I do not think the meter measures up to any one of those adjectives. However, it does meet all of the descriptions of a verb transitive category – to feel a sharp pain; to be acutely painful; to be punished.

Let me make myself clear. I am totally in favour of reducing energy use of all types whenever and wherever possible. However, choosing your time-of-use of electrical energy on the farm is not always possible or practical.

We are limited in the options to move electrical energy use time. For those of us without livestock or poultry, about the only significant energy use we can change is water heating. Most of us can put our water heater on a timer, so it can be ON only between 9 p.m. and 7 a.m. – the off-peak time period in both summer and winter. If we run out of hot water, installing a second water heater of the same type and size plumbed in parallel, or upsizing the water heater from a 40-gallon to a 60-gallon unit, is a relatively cheap solution that will provide payback within two years.

Do remember that, unlike our urban neighbours, we have to pump our own water and provide security lighting. Of those two, the security lighting does have some opportunity for reduction of wattage and thus energy usage.

Dairy operations. Virtually all across Ontario, dairy operations are becoming larger. Gone are the predominantly 40-cow herds. As herd size increases, so does the milking time and often the number of milkings per day. Shifting even one milking to off-peak is not likely to be practical or acceptable to most operators.

Yes the larger herd size has made heat recovery from milk a desirable and cost-effective method of heating water for a variety of uses at the dairy unit. Some of those uses might even include showering and laundry facilities attached or in close proximity to the dairy unit.

All other electrical use reductions will be relatively small, but should not be overlooked. Conservation by changing lighting systems can and does pay off.

Swine and poultry operations. Each operation must be considered individually. Energy use reductions or shifting time-of-use must be operation specific.

Many years ago, I suggested, tongue in cheek, that the environment in a fan-ventilated layer barn could be improved and energy saved by having the birds up and active during the colder night and letting them sleep during the warmer day. That idea was not adopted then, but maybe it should be reconsidered as we shift to time-of-use electricity pricing.

Many buildings housing poultry and swine are being designed to utilize natural ventilation. That is an excellent energy saver for older birds and animals, but is not feasible for the likes of brooding and farrowing, where a better controlled environmental temperature is essential.

Some progress has been made with the development of energy-efficient motors for ventilation and more energy-efficient lighting systems. For example, dimmable fluorescent bulbs are available. In addition, we are seeing more sophisticated motor control systems that reduce the heat required to preheat ventilation air and minimize heat wastage.

Heat exchangers to preheat incoming ventilation air with saturated exhaust air will be used more often.

As heat energy becomes more expensive, more money will be available for better designed heat exchangers or the operator will need to take time to clean (wash down) less sophisticated heat exchangers.

The major use issues. Many Ontario farms now have significant motor loads for grain drying and conditioning. These motor loads cannot be shifted for a number of reasons.
First, let us consider heated air grain drying. No owner/operator is willing to shut down a drying system when a crop is standing in the field or wagons and trucks are lined up at the scale house.

Secondly, if grain is being naturally air-dried or the moisture or grain mass temperature is being adjusted by aeration, airflow must be continuous to maintain grain quality and prevent spoilage.

Many of these larger power users will also be paying a demand charge, because they are drawing in excess of 50 kW during peak use periods. Demand is set after 20 minutes and the charge per kilowatt will be added to the hydro bill.

What are the solutions? Some staggering of load use may be possible when large motors are only going to be operated for a short time once or twice each day. The classic example is the electrical demand of a silo unloader and the associated feed handling system. When practical, feeding can be staggered from milking times to minimize the demand over 50 kilowatts.

Other livestock producers who grind feed or run a grain dryer are operating all or part of the farm electrical load on a standby generator system, which can be self-contained or operated by one of the farm tractors.

During the last two years, while offering grain drying seminars, we have been hearing more and more about the movement to power on-farm grain drying systems by dedicated standby generator systems that can also be used as back-up for the farm in the event of a power outage. This concept is likely to gain greater acceptance for other operations such as greenhouses.

Most farm operations now have some standby generation capability in order to provide a minimum supply of essential water, heat and ventilation for all livestock, poultry and greenhouse operations.

I visualize a much greater use of self-contained standby generation systems to operate full-time, or at least during the on-peak and mid-peak periods of all weekdays all year long.

Why bother? I just received a "Take Charge" notice with my Hydro One bill. It shows the Regulated Price Plan (RPP) and Time-Of-Use (TOU) prices for utilities using the smart meters starting Nov. 1, 2009. (See Figure 1)

Don't forget you must add delivery, regulatory and debt retirement charges to these figures. In addition, don't forget about the 9.2 per cent that is added to your Hydro One actual consumption figures to cover line losses. (Some utilities charge a lower percentage.)

When these costs are added up, and especially if a demand charge is added, the potential for saving money and having back-up power available makes on-farm generation of electricity very attractive.

Smart metering and TOU rates will cost most food producers more dollars with little opportunity to shift usage times to save energy and money. If many of us operate self-contained generating systems powered by diesel engines to provide our on-peak and possibly our mid-peak power as well, how will this scenario affect the Green Energy plan? BF

Agricultural engineer Ralph Winfield farms at Belmont in Elgin County.