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On Comparison of Grid-Connected and Off-the-Grid Houses


The energy to power plants/energy produced and deliverd to user's meter = 3.34

This does not include the energy to find the coal, get it out of the ground, process it, transport it to the power plant. That is about 5%

1.05 x 3.34 = 3.51, i.e., 72.5% is lost from A to Z!!! 

Also there are changes in embedded energy of the various systems from mine to meter.

My article states 75%

If you have better numbers, I will be glad to use them.

December 8, 2014    View Comment    

On Energy Efficiency and Renewables Are Lowest Risk, Cost Investments for Utilities

Reality Check:

Worldwide Energy Generation: As a result of gross world product, GWP, growth, world energy generation increased from 16,174 TWh in 2002 to 23,127 TWh in 2013, an increase of 43.0% in 12 years, about 3%/yr over 12 years. Analysis of the data shows:

- Near CO2-free, nuclear energy decreased from 16.5% in 2002 to 10.8% in 2013

- Fossil increased from 65.0% to 67.3%

- Hydro decreased from 16.7% to 16.4%

- RE increased from 1.6% to 5.3%

Worldwide RE Investments and RE Generation: The below, recently issued report presents an overview of worldwide RE investments from 2002 to 2013.

As a result of RE build-out investments of about $1,700 billion from 2002 to 2013 (excluding mostly “socialized” investments for grid adequacy, capacity adequacy, etc., of about $400 billion not mentioned in the report), worldwide RE generation increased from 1.6% to 5.3%, a 3.8% addition, of which:

- Wind increased from 0.3% to 2.7%

- Biomass from 0.9% to 1.8%

- Solar (PV + CSP) from 0.0% to 0.5%

- Geo from 0.3% to 0.3%

- Marine from 0% to 0%

Thus, the total generation (excluding nuclear) of Hydro + RE increased from 16.7 + 1.6 = 18.3% in 2002 to 16.4 + 5.3 = 21.7% in 2013. The 3.8% addition of worldwide RE generation required investments of 1.7 + 0.4  = $2.1 TRILLION from 2002 to 2013. The report data shows, the 12 - year trend of RE investments to reduce fossil energy generation and replace it with renewable energy generation would take many decades.

According to the report, worldwide RE investments were distributed as follows:





Asia, Oceania………..….25.3………..29.5…….....…43.3 (incl. Japan, Australia, etc.)


World Total……………279.0……….250.0………..214.0

From the above table, we can make the following observations:

- Worldwide RE investment has declined in the last 2 years, primarily in Europe.

- RE investment in Europe has collapsed, largely due to budget constraints resulting from about 12% unemployment, stagnant real household incomes, near-zero economic growth, near-zero inflation, and higher energy prices due to expensive RE policies. IMF managing director, Christine Lagarde, stated “a diet of high debt, low growth and high unemployment may become the new normal in Europe”.

- China became the largest RE investor, only because of RE investment backsliding by Europe and the US. China is catching up on RE investments, i.e., backsliding is not an option. Whereas China’s per capita GDP is low, its GDP is greater than of the US, on a purchasing power parity, PPP, basis.

- Other countries account for about 14% of the worldwide RE investment, which is of minor relevance regarding GW impact.,_2002-2013_(%25).png

Worldwide CO2 Emission Reduction Due to RE Investments: The $2.1 trillion of non-hydro RE investments over 12 years produced 1,234 TWh of electricity in 2013, about 3.8% of total energy generation. The addition of RE to the grid primarily displaces oil, gas and coal energy.If we generously assume all of the displaced energy in 2013 had CO2 emissions of about 0.7 kg/kWh, or 0.7 mmt/TWh, then, in 2013, the RE CO2 emission reduction would have been 0.7 x 1,234 mmt, or 0.7 x 100 x 1,234/36100 = 2.39%.

The 2.39% significantly overstates, because: 1) biomass, while claimed to be CO2-neutral, is in fact not so; 2) gas energy has CO2 emissions of about 0.55 kg/kWh; 3) balancing generating plants are operated less efficiently, i.e., emit more CO2/kWh; 4) the RE build-outs had embedded CO2 emissions; 5) most of the RE build-outs have short, less than 25 year useful service lives and need to be partially replaced causing additional embedded CO2 emissions.

NOTE: The increase of world CO2 emissions of 706 mmt in 2013 occurred despite the (overstated) reduction of 0.7 x 1,234 = 864 mmt due to RE in 2013.


December 7, 2014    View Comment    

On Wind Energy Primary Source of New U.S. Generating Capacity in October


What is important is not the MW, but the MWh.

How much energy would the addition of the MW be able to produce in one year and how much is that of the total US production?

December 4, 2014    View Comment    

On Comparison of Grid-Connected and Off-the-Grid Houses


Due to comments, such as yours, I did some revising, added an alternative 1A, expanded the notes at the end.

Also added LP-fired vented space heaters, which also serve to fire the engine generator; no diesel.

Please read the article again.

December 2, 2014    View Comment    

On Comparison of Grid-Connected and Off-the-Grid Houses


Battery performance in cold weather is bad as it it is. Using the car's heater  to stay warm would make it even worse. Range of a Chevy volt may decrease from optimal 38 miles to about 30 miles or less.

I had a BMW and the heater failed when I was in Vermont on a skiing weekend. Driving back the 200 miles was an ordeal. Good thing I had all my ski clothes on, but I still was freezing.

December 2, 2014    View Comment    

On Comparison of Grid-Connected and Off-the-Grid Houses


Thank you for your informative comments.

1) The revised text reads: About 75% of the fossil energy taken out of the ground to generate electricity never reaches the end user as electricity due to various losses.

BTW, Livermore may not have accounted for national T&D losses of about 7%, a sizable quantity that should have been mentioned. Also, Livermore may not have accounted for the losses from coal mine or gas well to power plant, about 5%.

2) "The extraction-condensing CHP plants commonly used to supply these networks are actually a type of heat pump but can deliver a CoP of 8-9".

Is normally the fuel for CHP plants coal, gas, oil, biomass? Does the generated electricity drive a heat pump that produces hot water for circulation?

Denmark is a flat country, mostly sandy soil, where distribution piping can easily be used to supply hot water to closely-spaced houses in communities.

Do you have any studies of CHP systems showing an efficiency analysis of the entire system (plant, distribution and buildings), using ACTUAL operating values for a period of say 3 to 5 years? I have done such studies of US CHP systems serving campus-style building complexes and all have poor efficiencies.

3) In Germany, where people have some experience building Passivhaus-style houses, the capital cost adder is given as 8 to 10%.

4) The article states charging the plug-in in winter may not be feasible; public charging stations would need to be used.

5) The space heating demand of 15 kWh/m2/yr can be partially satisfied by indoor heat sources (lights, cooking, computer, refrigerator heat, etc.), solar heat gain, and people. Not all of it needs to come from the solar panels.

A friend of mine has a passive solar house, very well insulated, etc., but not up to Passivhaus standards. He needs to open a window in the middle of the winter on a sunny day to prevent it getting too warm! That would reduce operating hours of the 1.5 kW heater, as a Passivhaus would be very slow to cool after the curtains are (automatically?) closed. He is not off the grid, has no PV panels, uses a small quantity of LP for space heating, cooking.

6) "As a policy matter........" I did not advocate not having large projects, but they have a drawback in that they do not directly involve the households, the people. It is an authoritarian, topdown approach, instead of a grass roots approach.

I look forward to your additional comments.

December 1, 2014    View Comment    

On Comparison of Grid-Connected and Off-the-Grid Houses


Thank you again for your valuable input. I was aware of the MIT article.

Embedded emissions would be spread out over many years, as is the case at present. Building structure EE measures would be spread out over at least 100 years.

I think pre-fab, multi-family, Passivhaus type, will become prevalent going forward, which will greatly imcrease quality control over stick-built. Customized pre-fab is highly advanced in Europe, particularly in Denmark, Sweden, Finland and Norway.

November 29, 2014    View Comment    

On Comparison of Grid-Connected and Off-the-Grid Houses



November 28, 2014    View Comment    

On Comparison of Grid-Connected and Off-the-Grid Houses


Thank you for your good comments.

We do not want to lose sight of the fact the "Off-the Grid" alternative is "near-zero CO2 emission".

The alternative "Energy-Efficient House, On-the-Grid, With Plug-in Vehicle" merely is a variant of the alternative  "Standard House, On-the-Grid, With Plug-in Vehicle" The latter is much more prevalent. I added a note to the text.

I have revised two paragraphs in the text.

An average standard house uses about 6,000 kWh/yr and one plug-in vehicle consumes about 12,000 mi x 0.30 kWh/mi = 3,600 kWh/yr, for a total consumption of 9,600kWh/yr. In New England, the PV solar system capacity would need to be about 10 kW to produce 10 kW x 8,760 hr/yr x capacity factor 0.12 = 10,512 kWh/yr. See Note 7. It would produce energy during the day and feed any excess into the grid, to be withdrawn at night to charge one or may be two plug-in vehicles.

Investment and Energy Cost Savings: The cost of the PV system would be about $40,000 less subsidies. Without PV solar system, annual bills would be for electricity 15 to 20 c/kWh x 6,000 kWh = $900 to $1200, plus for gasoline 12,000 mi x 1 gal/28 mpg x $3.50/gal = $1,500. With PV solar system, they would be minimal, but bills for space heating and domestic hot water, DHW, about $3,000/yr. (about $4,000 before tax), would remain. Over the long-term, electricity and gasoline prices may be increasing at 2 to 4 %/yr.

A 2000 sq ft Passivhaus-type energy-efficient house would not use 10 kWh per day, or 3650 kWh/yr. More likely usage would be about 7 kWh/d.

An 8 kW PV solar system would produce about 4.61 kWh on an overcast winterday. See Note 4. Not enough, ergo the generator is needed for a few hours. There may be 50 to 100 hours of generator operation during a few months of the winter. The rest of the year, the PV solar system would have greater outputs. Any time not enough energy is available, the plug-ins would be charged by public charging stations.

Re item 4: Your electricity use is 54800/15 = 3653 kWh, or 10 kWh/d. Either you have a small house with few electricity using devices, or live alone, or are not home much. Most households use about 5000 to 6000 kWh/yr. You mention the 3653 is 1/3 of your electricity. Where do you use the other 2/3?

November 28, 2014    View Comment    

On Comparison of Grid-Connected and Off-the-Grid Houses


See revised Note 4 with URL reference

November 28, 2014    View Comment    

On Comparison of Grid-Connected and Off-the-Grid Houses


See revised Note 4 with URL reference.


November 28, 2014    View Comment    

On Comparison of Grid-Connected and Off-the-Grid Houses


Thank you for your comment.

I did some rethinking and revised my assumptions.

See Note 4, which includes URL of reference.

November 28, 2014    View Comment