How much energy do we use vs do we waste?

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begreen

Mooderator
Staff member
Hearth Supporter
Nov 18, 2005
104,791
South Puget Sound, WA
The Dept of Energy just released its quadrennial report. This chart from page 22 simply blows my mind. On the left side are the inputs from various energy sources. On the right side is the result. The dark grey is the actual energy that gets used. The rejected energy (light grey) is waste! 2/3ds of what we obtain from the planet ends up as waste! Mind boggling when one considers this is the cheapest energy source we have available and yet we have been so slow to capitalize on it.
 

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Where is John Galt?
 
As you know, something like this chart has been coming out for ages. Every person that looks at it says I am going to become a millionaire. So far, not many have. If the solutions were there people would move on them.

I believe more than 2 of 11 parts of residential energy is wasted. So I question the rest of the chart.
 
meh. half of the 'wasted energy' comes from electricity generation, and is (pragmatically speaking) almost inevitable if we use heat engines to spin the gennies, due to thermodynamics. can only do much better if we go hotter, which is hard if you use this planet's air as an O2 source. The N2 cools the stream and will make nasty NOx if you go too high. Take it up with Mr. Entropy.

Of course, not a problem if we don't use heat engines--wind, hydro and PV displace 2x the 'primary' BTUs you might guess from their output.
 
Odd how the rest of the advanced industrialized world is already on the path toward figuring a lot of this out, yet we want to dispute it and keep our sacred temples in place.
 
A couple of years ago when researching mythical "clean coal" I came to the conclusion that electricity generated by coal on average delivered about 15% usable energy to the home from the energy input at the power plant. Average sub-critical electric power generation is 33% in the US (DOE). Line losses are another 8-15%. On the user end, power factor losses also can be close to 50% in some cases and 0% I think on pure resistive loads. Better design of home appliances and devices is cutting power factor losses significantly.

None of this of course takes into account the "true" cost of electricity generation from coal, which would include the cost of mining and transporting the coal, and the operating costs of the generation (plant cost, salaries, environmental costs, and so on). The bottom line is that the conversion of coal (and other fossil fuels) into electricity is very inefficient. Similar "true" costs also would have to be applied to other forms of electricity generation.

So, what's the alternative and why not make the change? We already know about many alternatives, but the big problem is the vested interest in the status quo, both by the producers and their cronies and the convenience factor to the user and their cronies. I'm using "crony" not in the negative sense but in the sense of all those dependent on the status quo. Shifts to new technology or energy systems mean winners and losers, and I think the losers right now make the rules and play the game.
 
jebatty said:
...On the user end, power factor losses also can be close to 50% in some cases and 0% I think on pure resistive loads. Better design of home appliances and devices is cutting power factor losses significantly....

On the local muni electrical distribution system we have installed automatic capacitor banks. They apply the capacitance necessary to keep the power factor high with smart technology. Much better than the old, "It is summer, lets engage the capacitors." A lot of that is done right at the motor in the industrial facilities. No reason these days to have low pf.

On this whole issue, the one telling point for me is the vast majority of homeowners in the nation do not even do the simple insulate, shade, low cost modifications easily available. I am not so sure about the vested interests etc. I just have to look at my neighbors. Ninety five per cent of whom use more energy than they have to and fail to make improvements that would save them money. These are people that need money for the most part.

When I returned home twenty years ago and built this house, some of the carpenters did not know I was a local. So after work in the bar they would make fun of my house for the double walls, radiant floor etc. My buddies would listen and laugh and then tell me what was going down. I never said anything, but since I was on site doing the electrical/mechanical I took the opportunity to share the simple payback I expected from different little features. To my knowledge, twenty years later, those carpenters have not constructed one single energy efficient home. Most of them have built their own homes by now and by all accounts they are devoid of any simple payback features. It is easy to blame the "interests", but not always accurate. For the most part, we are doing it to ourselves.
 
I think what Jimbo and BeGreen say illustrates our major problem in this country with respect to these issues.
As a society we only think short-term. If we can't get a payoff within 3-5 years we feel its not worth the trouble. I simply don't understand that viewpoint. I think its one that's been propagated by corporate America with "trickle down" effects into everyday life.

The only reason we've maintained our place in the world economy is through our continuing plundering of natural resources and technical innovation. Other countries that think medium- and long-term are going to pass us by. I think they are already beginning to.
 
When i fully retire my hobby will be building a net 0 home. May be weird for a hobby but thats just me.
 
I am not so sure about the vested interests etc.

The vested interest is the status quo which is diligently maintained by industrial, mining, oil interests to advance their profits through advertising to the consumer and lobbying government. Look what can happen when government and industry finally make a move: the rapid switch to high definition and the lcd/led TV's and the end of the cathode ray tube. Although initially vigorously fought by industry, when the buy-in came and advertising and price breaks to the consumer, the switch-over was dramatic.

The same thing can happen when the vested interests, and/or government, requires the switch to efficient, sustainable and clean energy sources. Whether it will happen is another matter.
 
trump said:
When i fully retire my hobby will be building a net 0 home. May be weird for a hobby but thats just me.

Sounds like a very satisfying 'hobby' to me. If I was younger I might be considering the same thing.
 
Semipro said:
I think what Jimbo and BeGreen say illustrates our major problem in this country with respect to these issues.
As a society we only think short-term. If we can't get a payoff within 3-5 years we feel its not worth the trouble. I simply don't understand that viewpoint. I think its one that's been propagated by corporate America with "trickle down" effects into everyday life.

The only reason we've maintained our place in the world economy is through our continuing plundering of natural resources and technical innovation. Other countries that think medium- and long-term are going to pass us by. I think they are already beginning to.

Ironically the payback for tightening up many houses is 3-5 yrs. It always amazes me how people come to this site looking for the biggest heater possible instead of considering closing down part of their mansion for the winter and addressing core issues of leakage. Ideally, we will wean ourselves from the habit of entitlement with the McMansions, cathedral ceilings and giant expanses of glass and replace it with common sense construction designed to keep the house's energy footprint low along with the long term costs of heating/cooling and lighting the place.
 
Im sure quite a few people LOST their homes to foreclosure and other causes when lower energy cost might have made the difference in keeping up the Pmts or Freezing. Thats some solid payback right there.
 
BeGreen said:
Odd how the rest of the advanced industrialized world is already on the path toward figuring a lot of this out, yet we want to dispute it and keep our sacred temples in place.

Not at all, I guess I was being unclear. I think we DO need to to do better, but I think calling the heat from a heat engine 'waste' is misleading, sorry. IF we leave a light on when we leave the house, or a door open in the winter, that is waste. We can get rid of that by a simple change of behavior, or a light timer or a door closing spring.

I was just pointing out that the biggest slices of the 'waste' on the chart is, curiously, those same sectors where the primary energy is being poured into heat engines to make electricity and spin our wheels....looking at the chart 46 out of 64 quads of waste. How much is thermodynamically required? When 'we' decided to build our economy on heat engines those 'losses' were baked in. They are not the result of some plant engineer or auto engineer being negligent, the eff of both turbines and IC engines has not been ignored for the last 100 years. We can make IC engines that are 25% more thermodynamically eff playing with temp and air ratio, reducing that bad waste, but they will pour out NOX (and wear out faster). When it gets cheaper to save the gas and capture the NOX, that tech is sitting on the table for rollout by the auto companies.

I know this was not your intent, but can we march down to the local power plant with pitchforks and tell them to stop 'wasting' 67% of the primary energy they burn to furnish us with juice? Can we demand our auto companies stop 'wasting' 75% in the engines of the cars we buy? Lets all shake our fists at thermodynamics.

To address this waste we all could...

--use co-gen electricity on our combustion devices, either large scale (district heating in cities) or small scale (cogen elec heaters in your basement).
--decide as a country we want to keep coal plants idle wen possible and gas turbines spinning, rather than the reverse we do currently. This is just a choice we make, which is rooted in antiquated habits and the misinformed idea that coal is 'cheap' (externalized costs not included properly). We could do this tomorrow and cut that electricity waste heat (and CO2) a lot.
--switch our elec supplier (if possible). If you live in a state with coal fed utilities, you could change your elec supplier for one that sells green or low-carbon juice by using hydro/wind/gas. You might pay a small premium, but those sources put comparatively little into that 'waste' stream. As a PA resident, I felt it was my duty to do this--I pay a premium. In quebec or the PNW, I suspect you can skip this step.

OR we could reduce our 'energy services'. You know, buy a smaller car or drive less (with an engine that prob still makes a similar proportion of waste heat)

Yeah, I guess thats my point--if we look only at this chart, it makes 'waste' look like something that is happening somewhere else, in a power plant, in an engine, and is not the consequence of our choices and actions--those are 'services', such a benign word. A question, look at 'residential', only 20% of the primary energy delivered to our homes is wasted....we rock! We are doing waaay better than those elec plants and nerdy auto engineers. I guess we don't need to do anything--turn up the AC and I'll sleep under a nice cozy blanket. I'm sorry, but in my opinion ALL of the BTUs we use to heat our homes are 'waste', not just the 20-30% we send up the flue (likely used in this chart). ALL of it. we could live n passive houses and get rid of it, almost ALL of it. It is waste, but this chart calls it a 'service' so its not bad.

Sorry you touched a nerve beeg. I think these charts confuse the issues a lot more than they help. The same approach is used to say that 'wind produces less than 1% of nation's total energy', when in fact it is >3% of total US electricity output, and thus _displaces_ 6-9% of primary fossil BTUs input to that sector! But that was a rant in an earlier thread. In other words, is it helpful that the 'wind input' goes through the box with the 67% waste cut? Does 67% of the elec produced by a wind turbine end up as waste, or is the 67% an average over the industry that obscures the smaller contribution to the waste made by renewable energy...hmmmm?
 
Cogeneration is a good example of better efficiency. So is more rail freight transit, better housing design, retrofit energy sealing, etc.. The point is that because of cheap, subsidized fuel we have become lazy in developing more efficient means of freight transportation, urban planning, home and office design. Taken all together, we are gluttons and need to go on a diet. True we will never be 100% efficient, but we can be a lot more intelligent about our designs. Conservation is the cheapest source of energy for us to develop at this time. Instead we are using substitutes like ethanol which is not helping at all with improving efficiency or the bottom line.
 
Fantastic post woodgeek. I enjoyed and agree with every bit of it.
 
JimboM said:
Where is John Galt?

There is a reason that is FICTION

Actually, many of the promises of increased efficiency have come true - and many more are on the way. Cars doubled in MPG and will probably double again in the next 10-20 years. Construction techniques have created homes and building that use 1/2 or less of the energy of the former generation. Boeings Dreamliners are even bringing efficiency to hauling thousands of tons into the sky!

Our electronic toys like computers (chips) and TV's (screens) are using vastly less energy per action processed. Vastly!

I think efficiency is happening and will naturally continue to do so. There may be burps along the way, but the trajectory seems to be set - at least, IMHO.
 
Despite huge improvements such as those Craig just pointed out, the original chart in this thread won't likely change much. The big "wasters" are built into the process.
 
Highbeam said:
Despite huge improvements such as those Craig just pointed out, the original chart in this thread won't likely change much. The big "wasters" are built into the process.

Agreed...at least not in our lifetimes. I also enjoyed woodgeek's post. As a Mechanical Engineer, I'll point out that the broad brush take-away from the original (interesting) chart is that overall, we're about 42% efficient. As woodgeek points out, as long as we keep relying on heat engines, that's really not a bad number...in fact, I think it obviously reflects the contributions of things like hydropower and other alternatives, because 42% is probably unachievable with a heat engine. Fossil fuel to electricity these days is probably around 33% or so. I remember our facetious rewrite of the laws of thermodynamics:

1. You can't win.
2. You can't break even.
3. You can't quit the game.

Shake your fists at the science of thermodynamics all you want, but if you're expecting heat engines to ever operate at eye-popping efficiencies, you really need to study and learn the subject rather than shaking a fist. You'll never change those laws, so what you need to change is how you provide the energy. Rick
 
When Edison got screwed by Detroit, we all got screwed.

We do have a choice these days though.

The local Chevy dealer has a Volt in the yard.

Even using a heat engine as part of a co-gen system and having an electric car (90% eff.), many of us can up our efficiency considerably.
 
Entropy may be a current limit in some areas, but the bigger issue I think is apathy. The engines of industry are only part of the problem. Lifestyle is another.
 
BeGreen said:
but the bigger issue I think is apathy.

Seems a little rough? A lot of people don't know how low some of the fruit is or are just too busy to deal with it. I'm not as familiar with residential, but there are a lot of relatively easy projects that pay for themselves quickly in commercial buildings often with nice incentives on top of it. The two biggest I see daily:

1. Retrofit all magnetic ballast light fixtures
2. Evaluate replacing old motors on HVAC units or any high hour running motors. The savings can be substantial especially when running 24/7.


With the incentives currently in place in a lot of states, there is no reason to not at least retrofit magnetic ballast lighting. The projects are relatively painless, the space will be better lit and it will pay for itself many times over.
 
My general rant is that most states have rebate programs for electrical savings but very few if any have similiar rebates for thermal energy savings. I know of many industrial and commercial buildings with uninsulated or underinsulated pipes. It reduces the owners initial capital cost up front but raises the long term operating cost. Most pipe insulation is sized for personel protection (typically less than 140 def F surface temp) instead of energy conversation. Even if it was installed corrrectly , half the time the insulation gets ripped out during repairs or the vapor barriers are compromised.

There have been a few studies that there is much better opportunity for thermal savings than electrical in most areas, but thermal energy is normally generated with competitive fuels so its not as easy to put a "systems benefit charge" as it is with regulated electric utility.

There is a new government standard for any boiler (except residential) that use liquid or solid fuel to force them to do energy audit if they are over a certain size, but no where in the rule do they have to implement the recomended changes in the audit. As an aside all these facilities have to register with the EPA and most dont even know that they have to and are currently in violation of the law.
 
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