or Connect
Green Options › Forums › Sustainable Living Discussions › Renewable Energy › importance of energy conservation
New Posts  All Forums:Forum Nav:

importance of energy conservation

post #1 of 3
Thread Starter 
From Luke at http://blog.plotwatt.com an article about the real benefit of conservation of electrical power. Quite interesting - don't know about the math but the direction is certainly correct. It shows the real importance of not using what is not needed.

"This is really important: energy saved can have multiplicative upstream impacts. A unit of energy (e.g. a kilowatt-hour) consumed by your television has much more impact than the same unit of energyproduced by your local power plant. This is a consequence both of inefficiencies in our system and of the laws and limitations of physics.

Inefficiency in the Home
Let’s look at the power it takes to illuminate a light bulb. We’ll start with a new term, the lumen. A lumen is a unit of measurement used to express the amount of useful (visible) light produced by a light bulb. It is important that we start there because lumens (not Watts) are what we want from our light bulbs. We’ll begin at the lumens and follow the electricity back to the power plant where we’ll discover just how much energy a light bulb wastes along the way.
Let’s say we want to create 1700 lumens of visible light. If we had a perfectly efficient light bulb, it would take about 2 Watts of electricity to produce 1700 lumens. Incandescent bulbs are far from being 
perfectly efficient. They are about 2% efficient at producing useful light. That means for every 1 Watt worth of useful light produced, 50 Watts are wasted on things like heat and invisible light. For incandescent light 1700 lumens requires a 100W bulb (i.e. 98% of the energy is wasted).

Power Generation Inefficiency
Finally, we have power plant losses. Extracting energy from just about any fuel source is an inefficient business. We generally burn a fuel and then use the heat generated to turn a turbine. In the US, across all electricity sources, we’re about 32% efficient (i.e. 68% wasted). So 107W requires 334W of input. All-in-all, it takes 334 W to make 2 W worth of useful light. From coal mine to illuminated living room, we are wasting 99.4% of the energy. Yikes. 

So what?
The repercussions of our gross inefficiencies are oft-neglected when it comes to clean energy thinking. We think that adding generation to the grid has the same impact as removing demand from the grid. In reality though, doing without the 2W worth of light is equivalent to removing the upstream need for 334 W worth of input or 107 W worth of generation. Similarly, increasing the end-use efficiency from 2% to 8% like we can do with CFLs, has huge upstream repercussions. Now, we’re still creating 1700 lumens of light, but it only takes a 25 W bulb, 27W of generation, and 84W of input."


 
post #2 of 3
That is really interesting.  It is nice to see it broken down like that, I knew about the inefficiencies but didn't have a comparable argument like this one.
post #3 of 3
Quote:
Originally Posted by Russ View Post

From Luke at http://blog.plotwatt.com an article about the real benefit of conservation of electrical power. Quite interesting - don't know about the math but the direction is certainly correct. It shows the real importance of not using what is not needed.

"This is really important: energy saved can have multiplicative upstream impacts. A unit of energy (e.g. a kilowatt-hour) consumed by your television has much more impact than the same unit of energyproduced by your local power plant. This is a consequence both of inefficiencies in our system and of the laws and limitations of physics.

Inefficiency in the Home
Let’s look at the power it takes to illuminate a light bulb. We’ll start with a new term, the lumen. A lumen is a unit of measurement used to express the amount of useful (visible) light produced by a light bulb. It is important that we start there because lumens (not Watts) are what we want from our light bulbs. We’ll begin at the lumens and follow the electricity back to the power plant where we’ll discover just how much energy a light bulb wastes along the way.
Let’s say we want to create 1700 lumens of visible light. If we had a perfectly efficient light bulb, it would take about 2 Watts of electricity to produce 1700 lumens. Incandescent bulbs are far from being 
perfectly efficient. They are about 2% efficient at producing useful light. That means for every 1 Watt worth of useful light produced, 50 Watts are wasted on things like heat and invisible light. For incandescent light 1700 lumens requires a 100W bulb (i.e. 98% of the energy is wasted).

Power Generation Inefficiency
Finally, we have power plant losses. Extracting energy from just about any fuel source is an inefficient business. We generally burn a fuel and then use the heat generated to turn a turbine. In the US, across all electricity sources, we’re about 32% efficient (i.e. 68% wasted). So 107W requires 334W of input. All-in-all, it takes 334 W to make 2 W worth of useful light. From coal mine to illuminated living room, we are wasting 99.4% of the energy. Yikes. 

So what?
The repercussions of our gross inefficiencies are oft-neglected when it comes to clean energy thinking. We think that adding generation to the grid has the same impact as removing demand from the grid. In reality though, doing without the 2W worth of light is equivalent to removing the upstream need for 334 W worth of input or 107 W worth of generation. Similarly, increasing the end-use efficiency from 2% to 8% like we can do with CFLs, has huge upstream repercussions. Now, we’re still creating 1700 lumens of light, but it only takes a 25 W bulb, 27W of generation, and 84W of input."


 

Yes, interesting post – I think both sites are great  – surprised by how much cool roof info there was  – how did they find time to research it all in just a few months.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Renewable Energy
Green Options › Forums › Sustainable Living Discussions › Renewable Energy › importance of energy conservation