Energizing the Smart Grid

Issue #102, June 2010
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Table of Contents:
What is the Smart Grid?

Energy Information Standards

Circuit Tracking Energy Monitors

Understanding Electric Bill Rates

Ten Energy Saving Tips

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What is the Smart Grid?
We hear talk in the news about the Smart Grid, the Smart Grid Initiative and Smart Meters.  Let's take a look at what each of these terms mean and what the home owner can expect to see from the outcome of this effort.

First, let's look at the purpose behind the creation of the Smart Grid.  If we understand the why, the how often times makes more sense.  Ever since deregulation and market driven pricing emerged for electric power, government regulators and utilities have been seeking a way to match consumption with generation.  Since most all grid power is consumed the instant it produced, achieving this match should delay construction of additional generation facilities and reduce the purchase of energy from higher priced sources.  In theory, this should delay or slow the rate of increase of electricity prices to the consumer.

In order to match consumption with generation utilities want to know who is using what amount of energy and when they are using it.  This is where the smart meter enters the picture.  Conventional residential meters simply record the number of kilowatt-hours as the energy passes through.  Monthly readings are taken by the utility and the electric bill is generated from the difference between the present and previous reading.

Smart meters, on the other hand, record the amount of energy used, the power quality and the power outage condition on a real-time or near real-time basis. This information is fed back to the utility on a continuous basis through a communications network.  This consumption feedback, or demand and energy status, gives the utility an accurate picture of what load they must match with generation.

The combination of this communications network integrated with the electrical distribution network is called the Smart Grid.  It encompasses power transmission and communications between utilities and other utilities and utilities and their customers which range from large industrial plants to individual homes.  In essence, it is huge. The combined effort between government, utility, industry, academic and various consumer groups to achieve this is called the Smart Grid Initiative.

What can the residential consumer or home owner expect from the Smart Grid Initiative?  First and foremost, electric rate structures will change.  Utilities will move away from conventional flat or tiered rates and gravitate toward time-of-use (TOU) rates.  These rates charge higher prices during periods of peak demand (hot summer afternoons) and lower prices during periods of lower demand (late at night).  The utility's objective will be to use price as an incentive to curb energy consumption behavior amongst customers.

For those who pay attention to their energy consumption this can be a path to a lower electric bill.  For those that don't, penalties will be paid in terms of higher electric bills. A home energy monitor system can serve as a very useful tool when deciding how to shift electric loads to take advantage of TOU rates.  For example, setting timers to turn on outdoor lighting or a pool pump when lower, off-peak rates go into effect is one way to lower cost.

Secondly, utilities will seek to gain more control of how power is delivered to and used by a customer.  Customers will need to understand constraints that may imposed by their electric tariff in the future.  Technology will emerge that will allow a utility to shut off appliances in your home to help balance load with generation.  If these caveats do emerge, they will be associated with the lowest priced rates.

Do you want your thermostat to be bumped up several degrees on a hot day without your input?  How well would your clothes fare if the washer or dryer were shut off mid-cycle?  What would happen to dinner plans if power to the range was delayed for an hour?  Although these are hypothetical examples, the desired level of control to be maintained by the consumer is the point.  

Pricing incentives are good as long as they don't cause undue interruptions in your life style.  As the Smart Grid emerges, be sure to have a clear understanding of the new rate structures and how energy is consumed in your home.


Energy Information Standards
One of the major efforts currently under way as part of the Smart Grid Initiative is the development of new standards for products that will be supporting the communication infrastructure within the Smart Grid. These standards will define how devices communicate electrical usage, power quality, pricing and device control information.
 
Within this set of standards, energy information that serves the grid is called managed energy and is controlled by the utilities.  Energy information, internal to a building, is referred to as collaborative energy and is controlled by the facility manager in a commercial or industrial environment or the home owner in the residential world.  The point of demarcation is the utility meter which needs to be able to send information to both managed and collaborative networks.

A number of organizations are developing standards pertinent to their area of interest in the Smart Grid arena. BACnet, EIS Alliance, LonWorksOpenADE, NIST and the ZIGbee Alliance are just some of the players.  I am involved with the EIS Alliance group.

Depending upon their area of expertise, each group works through the arduous and meticulous process of defining every imaginable energy information communication scenario with a different use case.  Separate use cases apply to the industrial, commercial and residential domains but there is some overlap.  From these use cases a set of requirements are developed that describe what is needed for each domain but do not yet delve into how it should be done.

Given the fact that a number of organizations are working on this endeavor simultaneously, some overlap occurs.  This overlap needs to be reconciled between groups before the set of requirements can be finalized.  When finalized, a draft specification is authored and posted for public and industry specific comment. Multiple iterations of the post and review process occur before the specification is submitted to a standards development organization (SDO) for approval.

SDO’s such as ASHRAE, NAESB, or OASIS are likely candidates to advance this process.  These ANSI certified organizations take the draft specification with comments and develop the final standard to be submitted to the Federal Energy Regulatory Commission (FERC) for approval.  The final standard defines the requirement and the method of implementation in such a way that manufacturers can produce products that will interface and communicate with each other, offering, seamless interoperability.  Typically this process takes years, but the Smart Grid Initiative is pushing aggressive timetables in order to compress it into months.

These standards will launch a plethora of new energy monitoring and tracking products in the commercial, industrial and residential markets. Home area networks will be able to offer a new level of control based on energy information.  Home energy monitoring will become more precise by moving from the whole house and circuit level to the appliance and device level with this new technology.



Circuit Tracking Energy Monitors

Several home energy monitors offer the capability to track individual circuits.  If an energy monitor has more that two channels, or current transformer (CT) inputs, it has the capability to track additional circuits.  The first two channels are always used to measure current from the two 120 volt feeders that enter the standard 120/240 volt main panel found in most homes.

The number of channels available for each meter featured in the circuit level monitor product table are shown on the Measurement Channels Avail. row.  These extra channels are typically used to track larger loads such as air conditioners, heat pumps, hot water heaters, the clothes dryer and/or the electric range.  However, a standard 200 amp panel normally has forty circuits.  Larger homes may have 400 amp service which uses two 200 amp panels and may branch to additional sub-panels.  Until now, it has not been possible to measure all of circuits with a reasonably priced home energy monitor.

Powerhouse Dynamics recently released a new product called the eMonitor  which we have added to the home energy monitor product table.  The eMonitor can measure 12, 24, 36 or 48 circuits depending upon the configuration you install.  Graphics and electrical data by circuit provide a wealth of information about how power is being consumed in the home.

The eMonitor contains an internal web server that connects to analysis software on the Web for a nominal subscription fee of $8 to $16 per month depending upon the number of circuits monitored.  It also has ZIGbee communications capability that will drive a future display and be able to exchange information with smart meters and devices including control instructions.  Interfaces with some home automation systems are under development according to Powerhouse Dynamics.

Chris Hunt of PowerDownus.com has installed the eMonitor in his home and was kind enough to share his review of the product.  He also put together a very informative video that covers installation and shows how to use the system.

Although the retail price of the eMonitor starts around $700 for the twelve circuit model, the added levels of information it provides will allow you to find new ways to reduce your energy cost.  This price point may be too high for a mid-sized home in the mid-south where energy costs 8 to 10 cents per kilowatt-hour.  However, a similar sized home in California paying 30 to 44 cents per kilowatt-hour may find it to be a wise investment.

A good rule of thumb when pricing energy monitors is to not spend more than twice your average monthly electric bill on a system.  This way, using a conservative estimate of 8-10 percent savings, you will recoup your energy monitor investment within two years.



Understanding Electric Bill Rates
Electric utility companies use a myriad of rates for the different types of customers and accounts they serve.  These rates are established in documents called Rate Schedules which the utility must file with each state's Public Service Commission or equivalent office.  The rate schedules must be approved by the PSC before the utility can apply them to your bill.

Large commercial and industrial accounts are billed a demand charge in addition to the kilowatt-hours they use.  The demand charge is based on the highest or peak amount of power used in any 15 or 30 minute interval in the month and is measured in kilowatts.  The demand charge can constitute 30 to 50 percent of the electric bill.

Residential bills are much smaller and generally do not have demand charges.  Most all residential electric bills are calculated with either a flat rate, a tiered rate or a time-of-use rate.  If you want to track cost with your plug-in meter, energy meter reader or home energy monitor, be sure they are capable of programming the type of rate you have.

A flat rate simply multiplies the total kilowatt-hours by a fixed rate to determine the energy cost on the bill.  This is usually accompanied by a fixed customer charge and  applicable state and local taxes.  Some bills may also contain a fuel cost adjustment which is the difference between the utility's estimated fuel cost and the actual cost of fuel it took to generate the power.  This can appear as a charge or a credit based upon fluctuations in fuel price.

A tiered rate charges one rate for a fixed set of kilowatt-hours and a second rate for all kilowatt-hours used over that amount.  These rates can have more than two tiers.  For example, a three-tiered might be structured like this: the first 800 KWh is charged at 10¢ per KWh, the next 1,000 KWh is charged at 9.5¢ and all usage over 1,800 KWh is charged 8.75¢ per KWh.  The time at which the power was used does not affect a tiered rate, only the total number of kilowatt-hours used.

Time-of-use (TOU) rates, on the other hand are time sensitive.  They have a specific peak period when a higher rate is applied and an off-peak period when a lower rate is applied.  More complex rates may contain a shoulder rate which applies to a third period between peak and off-peak rates.  However, this is not common in residential rates.  Peak periods do not apply on weekends and holidays.

An example of a TOU rate may read something like this: The peak period shall be from 10:00 AM to 8:00 PM from May 1 through October 31 and from 6:00 AM to 10:00 AM and from 2:00 PM to 8:00 PM from November 1 through April 30 excluding weekends and holidays.  All other periods shall be off-peak.  The peak period charge shall be 12¢ per KWh and the off-peak period charge shall be 9¢ per KWh.

Most residential rates are flat or tiered at this time.  As smart meters are deployed utilities will introduce more and more TOU rates to use price as an incentive to curb peak consumption.  For those who understand how their power is used, and are able to shift usage from peak to off-peak periods, TOU rates can be a benefit.  However, those that do not pay attention to how their power is used are destined to pay higher electric bills.



Ten Energy Saving Tips
Now that summer is arriving here are a few energy saving tips to keep in mind...

1.  Be sure your central air conditioner or heat pump is fully charged with refrigerant.  Ask for an annual inspection from your HVAC contractor  Low levels of refrigerant will cause the compressor to run longer to achieve the desired level of cooling

2.  If you are replacing an air conditioner or heat pump be sure to not over size it.  An air conditioner needs to cycle on and off frequently to keep the humidity down.  An over-sized compressor costs more to run and causes higher levels of humidity due to less frequent cycling.  Humid air requires more energy to cool than dry air.

3.  Shut the door and close the vents in rooms you use infrequently.  This reduces the total volume of air to be conditioned by your HVAC system.

4.  Add a layer of blown insulation in your attic.  The blown insulation creates a uniform blanket without any cracks and voids.  It can easily double the R-factor rating of insulaton bats alone.

5. Check and replace worn weather stripping around exterior doors.  Cool air escapes in summer and cold air penetrates in winter taxing your HVAC system year round.

6.  Place an insulation jacket around your hot water heater and wrap hot water pipes with pre-formed insulation - especially if you have an instant hot water system that maintains convective or pump driven circulation.

7. Electric hot water heating constitutes about 20% of a home energy electric bill. Consider a solar collector to help heat water during the day and a timer to shut off the hot water circuit when not in use at night.

8. If considering replacement windows choose double pane low-e (low emissivity) with  vinyl frames to minimize heat transfer and filter out UV light.  If you live in a colder climate select argon gas filled low-e windows to reduce heat loss in winter.  Triple pane windows can reduce this heat loss even further.

9.  If designing a home or remodeling, plan to construct overhangs, porch roofs or awnings above west facing windows to reduce afternoon heat gain.  If already built, install drapes to block afternoon sunlight from penetrating western exposures in summer.  

10.  Plan room lighting with at least two sources on separate switches. An array of recessed lights can light the room quite well but will consume more kilowatt-hours.  Provide a second source such as counter top lights, vanity lights or a 40-60 watt twin-bulb overhead fixture when full illumination is not required.  


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