Examples of revision

Basic ideas:
Sentence: "Known `character'" → drives present-tense active verb →⇒ new material. [noun->verb->noun]
Remove unnecessary adjectives and all adverbs.
Cut while preserving meaning.

Orig.
Renewable energy resources such as hydro, solar, and wind power are being looked at to see if it is possible to start really transitioning from producing electricity from fossil fuels to producing electricity from renewable resources, specifically solar power. One big aspect of this is looking at what the cost would be for solar power to produce 10% of the current US electricity usage, which is calculated to be approximately $53.7 billion per year based off of 2011 population and cost information.

Revd.
Replacing 10% of electricity with solar PV is attractive since the sun shines when we need peak power. Yearly consumed electricity is 4 PWh. [at a retail cost of 360 billion dolars]. Using the solar LCOE (125 $/MWh) ten percent of consumed electricity could be solarly generated for $50 billion.

Orig.
This number of $53.7 billion per year to provide 10% of US electricity usage with solar power means little to most people, until it’s compared with cost of 10% of US electricity usage currently. The cost of electricity was an average of 9.90 cents per kWh (across all sectors such as residential, commercial, industrial), and using this to calculate the cost of 10% of US electricity (all forms of electrical power included) it would result in $40.9 billion dollars. From this comparison, one can see that to increase the portion of electricity made by solar power to 10% would require paying an additional $12.8 billion as a country, or more than 25% more than you are already paying for electricity.

Revd.
This number -- $50 billion per year -- means little without comparison to the current cost of elecricity. The rate for electricity, averaged over all sectors, $9.90 per kWh, would cost $40 billion for ten per cent of electricity. Replacing that power with solar costs an extra $10 billion

Orig.
As seen from the numbers above, it would be very costly to suddenly bump our portion of electricity produced from solar power to 10% now, but it might be more reasonable in the future. Advances in solar power technology are being made that might make this more feasible. The cost of solar power to produce 10% of US electricity usage is calculated to be $53.7 billion per year, based off 2011 energy consumption and solar power cost. This is significantly higher than the actual cost of 10% of the U.S electricity usage in 2011, which is around $40.9 billion and 25% less than the $53.7 billion.

Revd.
The extra cost of using solar electricity for peak power seems costly now, but might the future change our opinion?

revised essay

Replacing 10% of electricity with solar PV is attractive since the sun shines when we need peak power. Yearly consumed electricity is 4 PWh. [at a retail cost of 360 billion dolars]. Using the solar LCOE (125 $/MWh) ten percent of consumed electricity could be solarly generated for $50 billion.

This number -- $50 billion per year -- means little without comparison to the current cost of elecricity. The rate for electricity, averaged over all sectors, $9.90 per kWh, would cost $40 billion for ten per cent of electricity. Replacing that power with solar costs an extra $10 billion

The extra cost of using solar electricity for peak power seems costly now, but might the future change our opinion? Three factors may be relevant.

(1) Current peak power electricity is generated with fossil fuel, usually natural gas. Our present bonanza of US-fracked natural gas won't maintain its current cost; moreover its long-lived alternative -- coal -- will cost more to produce with the decreased pollution.

(2) Fluctuations in the demand has stimulated many approaches to smooth out the demand curve. The figure illustrates the conficting approaches that depend on the amount of power needed and time-scale of desired response. Differing size utilities and nature of the coupling between them will evolve.

3) Predicting the reduction in the price of solar PV is confusing as economic estimates based on US production data can't deal with at least two factors: (a) what initiative China will make such as their earlier $40-plus billion spent to make their silicon PV competitive and (b) the strong competition to develope alternative semiconductors and designs for solar PV. The US DOE Sunshot goal of a dollar per W is is simply a goal with weak technical basis.

To solarly produce ten percent of electricity will cost an extra $10 billion annually for added solar PV power, a number that might very well decrease with possible/probable rising cost of fossil fuel and decreasing price of solar PV.

P.S. How much solar is there? not enough

Revising Topic sentences

Orig

Revising

Alternate:

Tightening

Orig: Ethanol use in cars is a viable additive but not as a replacement for gasoline.

Revising: Modified car engines can use gasoline-ethanol mixtures but at both greater cost and engine damage and lesser efficency and safety.

Alternate: Adding renewable ethanol can lessen both the demand for nonrenewable gasoline and the generation of greenouse gases; but at great cost and motor damage

Tightening:Adding ethanol to gasoline cuts gas use and greenhouse gases but increases overall costs (e.g., fuel and motor lifetime).

and

Orig The production of hydrogen as an energy source will need to be vastly improved to allow for expansion of the hydrogen fuel market. The common methods of hydrogen production are inefficient, expensive and harmful to environment.

Revising The current sources of hydrogen are easily characterized: by-product of petroleum refining-largest-primary source now; coal-fired power plants-such low efficiency that CO2 by-product rule it out; natural gas-too limited to be steady source; algae-requires major research and development to pull it off; electrolysis-only if electric power is free.

Tightening Hydrogen for fuel cells will intially come as by product from petroleum refining and algae, with inventiveness and govt. support; other approaches are hopeless.


Your comments and suggestions are appreciated.

To cite this page:

<http://www.physics.ohio-state.edu/~wilkins.5/energy/Resources/Lectures/rev15.html>
[Sunday, 17-Dec-2017 07:00:37 EST]
Edited by: wilkins@mps.ohio-state.edu on Monday, 07-Nov-2016 13:14:13 EST