Conservation can cut 30 times more CO2 per dollar

by Ginosar  

The rapid advance of Global Warming and emitting 70 million tons of CO2 daily dictate that we should proceed immediately to cut CO2 as rapidly as possible. By using simple conservation we can more rapidly than any other approach cut down CO2 at the fastest possible rate with the least cost. No training, no material or skill shortages. Conservation can be as much as 30 times cheaper than photovoltaic, much faster to achieve, retains all the money in the US, and can employ locally the largest number of people.

This is for illustration only, all numbers are ballpark.

Options reviewed:

1. Replace 5% of US electricity from coal by PV cost: $ 923 Billion

2. Reducing same CO2 emissions by attic insulation cost: $ 29 B


CONSERVATION can be 30 times more COST EFFECTIVE than PV

Thus we can cut CO2 emissions 30 times more per dollar


1. Federal tax rebate for PV at 30% rate could cost: $ 277 B

Therefore: Sensible Federal approach to reduce CO2 could:

A. Achieve the same CO2 reduction with just 3% of the cost by Conservation

B. Using just the 30% federal tax rebate directly we can achieve TEN TIMES the CO2 reduction as federal support for  PV.

To maximize results cost should be an important consideration since we never will have sufficient funds to do all the things we need to do to reduce global warming. The US can not afford the luxury of using high cost, appealing approach when reliable, proven, boring approach can reduce CO2 by 32 times less expensive means.

Dr. Matania Ginosar

Environmental Scientist & Electrical Engineer

Mailed Feb 09


Calculations and Background:

Federal support alone for PV could cost $277 billion

A. INITIAL CAPITAL ONLY: PV has many additional costs that are not calculated here such as maintenance and repair, which are not required with conservation. Conservation quality declines very little with time, PV output decays faster with life.

Life cycle cost has demonstrated even more benefits for Conservation.

US electric consumption 4 billion MWH/yr

Replace 5% of US electricity from coal by PV, half on private home roofs, half commercial. All PV units here are 1 kW.

1. PV Roof installations assume $7000/kW average

PV price has not declined as assumed: In 2005 cost of roof-installed kW was $8,000; today it is about $9500. Now with substantial increase in subsidies and increased demand, system price is likely to go up, not down.

Assume half of PV installations on roofs, and despite that price is not dropping in last 4 years but going up, assume price will drop to an average of $7000/kW over the next few years.

2. Commercial at $5000/kW average (currently $7,000)

PV Output per KW US average,

Roof PV 1200 KWh/yr = 1.2 MWH/yr

Commercial, not in cloudy areas: 1.4 MWh/yr

Combine average output per kW: 1.3 MWh/yr

Cost average:  $6000/ kW


5% of US 4 billions MWH/yr = 200 million MWh/yr needed from PV

Divide by PV average output of 1.3 MWh/yr = 154 million PV kW units installed

Total PV cost: 154 M units times average cost of $ 6000 per kW = $ 923 Billion Federal support for PV at 30% = $277 billion.


Conservation could achieves same CO2 reduction: $ 29 B

Potential Global warming impacts of mass PV installations:

Producing, installing 154 Million PV units generates 300 million tons of CO2

To curtail GW our immediate national goal should be to cut the maximum amount of Global Warming gases above all! And to do it as fast as possible.

Note also that crystalline silicon PV takes some 6 years for energy payback; the highest of any alternative energy, this will increase GHG rapidly during PV installation. Previous detailed studies by supporters of PV show energy payback in the range of 8 to 11 years. Here we use just 5 years for energy payback. As long as we use current crystalline silicon technology, it is very difficult to reduce energy payback. Making highly refined silicon wafers that can have high efficiency and reasonable life expectancy requires considerable amount of electricity. In addition manufacturing and installations of additional system parts consume a lot of fossil energy. Note also that for next ten years 50% of US electricity will continue to come from coal, and 20% from natural gas thus electricity production will continue to emit high amounts of CO2.

Reducing the PV energy payback period will have little impact on these cost calculations.

Building insulation, attics and walls, could use just shredded newspaper (which often is buried because market price for recycling is too low, or is shipped to China) coated with fire preventions. It is blown by a very simple machine into the attic; it takes less than one hour per attic. It uses moderate and low skilled local labor.


Cost should be an important consideration since we never will have sufficient funds to do all the things we need to do to reduce global warming. The US can not afford the luxury of using high cost, appealing approach when reliable, proven, boring approach can reduce CO2 by possibly 30 times less expensive means.

Most of the federal financial resources for CO2 reduction should be directed instead, to support and pay for massive conservation and efficiency across the USA.

Federal support for R&D for advanced solar and other technologies that can reduce CO2 at reasonable costs should be substantially increased.

Estimates of Conservation - Attic Insulation example.

In most cases the best alternatives energy systems are energy efficiency, and conservation.

Every kWh saved is one less kWh needed to be produced, controlled and transmitted. Also, utilities need less capacity with conservation since insulated houses would not ever required extra energy. Houses with PV do require additional utility energy at night, when systems fail or weather dictates.

Attic insulation could be 32 times more cost effective than solar - silicon PV.

Other conservation measures may be more expensive.

Conservation cost remains in US:

Total attic insulation costs, labor and material, remain in US. And ¾ of cost is for local, low skill labor, which is abundant in the US. It is effective all the time 24/7

PV capital flows partially overseas:

Silicon panels, 45% of PV systems cost, are often manufactured abroad, thus exporting US capital overseas adding to our national balance of payment problem.

More people employed per dollar investment by conservation - reducing unemployment

Insulation can be used effectively across all areas of the country, independent of sun availability.

Case study: Typical 1970's home in Sacramento with the then-typical limited attic insulation of R13 or less. Calculations of an actual Sacramento home, with technical support from two independent utility personnel, SMUD, and PG&E IN 2002, prices updated to 2008.

Cost per attic insulation upgrade from R13 to R38, $1,500 total cost for 1750 sqft home. Just $600 if done by owner, as the author did.

Insulation useful life = life of house, over 50 years

Conservation direct Energy Savings:

1. Heating season- 120 days; natural gas: 3 Therm /day, yearly saving, = 360 Therm/yr saved

2. during cooling season - 120 days, average use (per PG&E) is 1000 kWh /mo, savings can be half of that: 500 KWh/m x 4 month; verified for a typical area in SMUD Sacramento too.

Energy saved a year: 360 Therm gas plus 2,000 kWh

For life of home: electricity: 50yr X 2,000 kWh =100,000 kWh = 95 tons of CO2

Gas: 360 Therm x 50 year = 18,000 Therm, x 12 pound/T = 108 tons of CO2

Total reduction: 203 tons CO2

(With mass contracts this cost could be noticeably reduced.)


PV energy production 25 years life less five years energy payback, net 20 years times 1.3 MWh/ yr

26,000 kWh x 0.95 KG/ kWh = 25 tons of CO2 for system life

All electrical comparison for CO2 from Coal power plants.


CO2 reduction by attic insulation 203 tons, 8 to 1 better for conservation

Cost PV:  $6,000/ kW; Conservation: $1500, 4 to 1 better for conservation

Therefore, attic insulation could be 32 times more cost effective than PV in reducing GHG.


Another way of saying it:

Attic insulation can reduce 32 times more CO2  than PV per dollar.


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