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提高能源使用效率，能減少污染和溫室氣體排放、節省資金，及提供就業機會。比起大型的發電廠，它們對社會造成的危險，也小得多。例如，政府根據對未來需求的預測，建造了大型發電廠，後來經濟又嚴重萎縮了，這該怎麼辦呢？大多數供應方要求長期進行投資，所以就得有人為一段時間內並不需要的發電廠付錢，而不管這是不是必要的需求。相反的，需求管理更為靈活，可以按需要上下變動，跟著經濟上下波動。舉例來說，能量利用效率較高的建築標準能在經濟繁榮時節約很多能源，而且那時候最需要節約能源（因為更多的人在使用更多的能量），而當經濟停滯時就節約得少些，那時侯不太需要節約能源。
透過省電來節約資金的潛力不可限量。根據美國洛磯山協會的效率研究小之統計，全世界每年用在電上的花費高達5000億美元。能源專家認為，提高能源效率的方法能夠節約30∼50%的能源消耗，甚至更多（如在仍使用低效、陳舊技術的發展中國家，其能源節約將更大幅高於此數據）。
高效的方法並不是免費的，但和新的電供應比較起來，還是很便宜。除了成本低外，還能帶來其他的經濟利益。效用報告指出，實施各種節電措施的平均成本大約是每度電成本的2%，設計的最好的專案比這要便宜好多倍。相反，現存的發電廠每發一度電，成本都高於美金5分（甚至會高達20分），這還不包括修復發電廠對環境造成的破壞之成本。
許多研究顯示，與建設新發電廠相比，採用高效的方法還能夠創造更多就業機會。與建築工人建設一座發電廠來為一百萬座建築物提供所需能量相比，同樣一百萬座建築物得有更多的能源審計員來檢查、作出評論、增加絕緣、安裝有效的燈光照明等等。
在某些國家（尤其是那些使用能源最多的國家），需求管理已經非常先進了。例如，根據洛磯山協會的統計，自1973年以來，美國因採用需求管理而節約的新能源是家用能源供應擴展的新能源總數的四倍還多。如果他們照1973年的速度用電，與他們總共的花費比較起來，已經節約的能源使得美國每年少支付2000億美元的電費。
這似乎難以相信，儘管發展中國家的總體人均能源使用量非常低，但它們節約能源的機會非常多。一個原因就是，發展中國家並不像已開發國家那樣經常地替換或保養舊機器，這意味著這些效率已經很低的機器，用起來比剛買的時候的效率更低了。發展中國家還成了的低效機器或過時技術的「傾銷地」，而這些在先進國家卻不允許再使用。比方說，貧窮的國家購買廉價的空調似乎是非常合理的，這些空調沒有達到美國的效率標準，因此就不能在美國銷售，但是同樣廉價的空調卻要求更多的發電廠來為它們提供電力，而且它們每使用一次，消費者就得掏出更多的錢來。到最後，既然大多數發展中國家政府最關切的，就是讓全國人民都有水電可用，那麼他們在制定提高效率的標準和政策方面，就顯得步伐緩慢。因此，新的建築和當地生產的設備效率可能相當的低。
版權歸屬國際河網IRN，環境信託基金會（陶俊 譯， 李傑、張正慈 審校）
中英對照全文：http://news.ngo.org.tw/issue/water/2001/issue-water-irn01070901.htm
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Energy efficiency measures can reduce pollution and greenhouse gas emissions, save money and create jobs. They also pose significantly less risk for society than large-scale power plants. For example, what happens if the government has committed to build a large-scale power plant in anticipation of future needs and then the economy suffers a serious downturn? Most supply-side investments require long-term commitments, so someone is going to pay for that unneeded power plant for some time to come, whether it is needed or not. In contrast, demand management efforts are much more flexible, and can be ramped up and down as needed, tracking the economy's ups and downs. For example, energy-efficient building standards will provide lots of energy savings when the economy is booming and the energy savings are needed the most (because more people are using more energy), and much lower savings when the economy is stagnant and energy savings are less important.
The potential for saving money by saving electricity is enormous. Electricity costs the world more than $500 billion annually, according to the US-based efficiency research group the Rocky Mountain Institute. Energy experts believe that energy efficiency measures could save 30-50 percent or more (and even greater in developing countries that are still using old, inefficient technologies).
Efficiency measures are not free, but they are very cheap compared to new power supply - and bring other economic benefits besides lower costs. Utilities report that the average cost of implementing electricity savings of all kinds has been 2~ per kilowatt-hour (kWh), and the best-designed programmes are many times cheaper than that. In contrast, each kWh generated by an existing power plant costs upwards of 5 cents (and as high as 20 cents), and that does not include the cost of repairing the environmental impacts of energy plants.
Numerous studies have shown that undertaking efficiency measures also brings more jobs than building new power plants. It takes many more energy auditors to go through one million buildings, make recommendations, add insulation, install efficient lighting, etc. than it takes construction workers to build the power plants necessary to provide energy to the same one million buildings.
In some countries (especially those using the most energy), demand management has advanced significantly. For example, since 1973, the United States has gotten more than four times as much new energy from demand management savings as from all expansions of domestic energy supplies put together, according to the Rocky Mountain Institute. The energy savings already achieved have cut Americans' energy bills by more than $200 billion a year, compared to what they would collectively be spending if they used energy at the same rate as in 1973.
Although it may seem hard to believe, the opportunity for energy savings in developing countries is very high, despite their overall low per-capita use of energy. One reason is because older equipment is not replaced or maintained as often as in richer nations, meaning that already-inefficient machinery is operating even more inefficiently than when it was first purchased. Developing countries have also become "dumping grounds" for inefficient appliances or technologies that are no longer allowed in developed countries. It may seem logical for poor countries to buy, say, cheap air conditioners that do not meet US efficiency standards and therefore can no longer be sold there, but those same cheap air conditioners will require more power plants to run them - and more money out of consumers' pockets every time they are used. Finally, since most developing nation governments have been most concerned about bringing services to unserved citizens, they have been slower to develop standards and policies to increase efficiency. Therefore, new buildings and locally manufactured equipment may be very inefficient.
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