Negawatt power

From Wikipedia, the free encyclopedia

 Please help improve this article or section by expanding it.
Further information might be found on the talk page or at requests for expansion. (December 2007)

Negawatt power is a term coined and introduced by Amory Lovins in a 1989 speech. This technique works by investing to reduce electricity demand instead of investing to increase electricity generation capacity. This "virtual generation" method can supply growth of supply by improving the efficiency of existing electrical equipment rather than by building new power stations.

Energy consumers may also reduce energy consumption for a few hours to "generate" negawatts - hypothetical tradeable units of saved energy. By shutting off air conditioners during the peak electrical load hours - summer afternoons - peak electricity consumption can be reduced. This reduction in consumption is referred to as a negawatt.

An electricity supplier that has a requirement for additional supply capacity can invite suppliers to quote for the supply of that electricity and can equally invite it's customers to quote to reduce their demand. The electricity supplier can then compare these quotations to establish the most economic alternative. This comparison can refer to peak load management - how much per additional kW to get the power company through the peak load due to air conditioning on an unusually hot day - or may refer to longer term investiments - comparing the cost of building a new power station with the cost of providing customers with low energy light bulbs.

In theory these Negawatts can be aggregated and an arbitrage market could be created to trade these.


Contents

[edit] Origin of negawatt

While reading a Colorado Public Utilities Commission report, Amory Lovins found a typo "negawatt" (the report had meant "megawatt"). Lovins saw the typo as a way to describe a watt of electricity that wasn't created, due to energy efficiency.[1]

[edit] Market

A genuine market for negawatts requires regulatory failure elsewhere: the price of electricity at peak times must be lower than the marginal cost of supplying additional peak demand, or there must be constraints on the installation of new capacity.

Establishing a market for the trade of Negawatts may require enabling legislation and cooperation between primary producers, distributors, traders and consumers when these parties have conflicting interests. For instance generators income is commonly derived from selling electricity and their cash flow may be reduced by trade in efficiencies, however increasing supply by raising consumption efficiency is less expensive generally than building extra generating capacity. New markets have developed in several regions across the United States to allow "demand side resources" to participate in wholesale energy markets. These markets are commonly referred to as demand response.

[edit] Negajoule

A negawatt is a concept related to power and electrical generating capacity. A similar concept applies to energy, with potential consumers being rewarded for lowering consumption at any time, rather than just at peak times: this could then be labeled negajoules or negawatt-hours. [2]

[edit] Demand Response and Energy Efficiency

[edit] NYISO

  • Day Ahead Demand Response Program
  • Emergency Demand Response Program
  • Special Case Resources

[edit] Technology or installation limitations

[edit] Compact fluorescent light bulbs

Main article: Compact fluorescent light bulb#Design compromises and challenges

While Compact fluorescent light bulbs can fit into any socket designed for traditional incandescent bulbs, some lighting fixtures tuck the socket into spaces too compact for CF bulbs, which are still slightly larger than traditional lights.

In an initial house construction, this issue can be completely avoided by taking caution when purchasing or designing light fixtures.

Also, most CF bulbs require additional electronics in order to work with standard dimmer switches or timers.

[edit] Geothermal Heat Pumps

The single greatest issue for GHPs are the installation requirements. They are as follows:

  • Available land for installation: Vertical bore systems avoid this as they only need 20ft between wells/columns. Horizontal systems require substantially more space.
  • Structure size: As the house or business increases in size substantially, there is a diminishing return on investment (ROI) as there is the probability that the installed system will require 2 or more main system units as well as additional/duplicate system management implements such as thermostats.
  • Heat source/Cooling sink: Impacted mostly by climate, but occasionally by geologic conditions. The ground must have a reasonable constant temperature and there needs to be as high a surface contact as possible for heat exchange to actually take place. This is usually facilitated by constantly introducing water into the horizontal field or in vertical systems by using a desiccant like montmorillonite that absorbs naturally present/flowing water during the early life of the installation.

[edit] Lighting

Type : Energy to Lighting Efficiency

[edit] Heating/Cooling/Hot water

[edit] Smart control

Includes:

  • Motion sensor light switches and outdoor lights
  • Timer Light Switches
  • Fully programmable thermostats
  • Whole home computer controlled intelligent device management/automation. See Home automation

[edit] Geothermal exchange heat pump (GHP)

In theory, Heat Pumps (the category also includes air conditioners) are producing heat (or removing heat and placing it elsewhere) at a rate in excess of 100%. This means that there is more heat energy moved around than it would take to produce the same heat energy with an electric element. The reference to the electric element is important as electric heat is accepted as 100% efficient. Due to the laws of thermodynamics, the greater the extreme in temperature, the faster the movement of heat energy.

With this in mind, GHPs are always working with a reasonable to excellent difference in temperature between the coolant and the ground[citation needed]. GHPs that are based on direct expansion technology [5] are usually the most efficient due to the nature of a device that has fewer transitional stages. The previous link shows that a DX heatpump can, in ideal conditions, achieve a COP (Coefficient of Performance) as high as 3.8 or 380% efficient. In a more fundamental form, this means that if you were to compare electric to a DX GHP, you would only have to spend, in ideal conditions, 26% of what you would have to spend to heat with electric baseboards.

Depending on when one installs a GHP (during initial construction or in a retrofit), you will experience a different ROI. Additional sources of variability are: The cost of electricity, local tax rates, the heating and cooling needs based on geographic location and the variability of installation costs from the contractor.

Initial installations can experience a ROI as short as three years and as long as seven years. As an example, the cost of power [6] in the province of New Brunswick, Canada has risen so high that the ROI is easily achieved in less than five years.

An additional note on initial installation, the cost to be factored against the reduced energy costs is the difference in cost between the systems that are being considered as a heating/cooling solution.

A retrofit installation typically has a larger cost of implementation and therefore will have a longer ROI. The cost of such an endeavor is too variable to post extensive or even expected ROIs for every situation, proceed knowing that the closer a house or structure is to modern forced air standards, the closer to initial construction the ROI will be.

Beyond DX technology, classical closed loop liquid coolant GHPs are easily capable of reaching the same efficiencies. [7] The only detractor is the restrictions on construction that may present themselves using this subform of heat transfer.

[edit] See also

energy Portal

[edit] External links

[edit] References

  1. ^ Kolbert, Elizabeth. "Mr. Green: Environmentalism's most optimistic guru." The New Yorker, 2007-1-22.
  2. ^ Presentation on European Green Paper on Energy Efficiency p 12
  3. ^ [1][dead link]
  4. ^ Geothermal Heat Pumps Key Product Criteria : ENERGY STAR
  5. ^ [2][dead link]
  6. ^ Rates - Énergie NB Power
  7. ^ [3][dead link]
Languages