R-Value and Wind Turbines - please clarify.

New to renewable energy? Have questions? Here's a great place to ask them and view information about wind and solar power basics.

R-Value and Wind Turbines - please clarify.

Postby stewart1000 » Sat Mar 19, 2016 11:18 am

I am hoping to get some help on a topic i cant seem to work out.
i have been reading "Forecasting the Future of Alternative Energy Technologies Using Economic Payback Curves." by Nowakowski, Gary A. and Hahn, Michael P.

in this journal article they speak of R-Values increasing as the product develops. I understand R-value in relation to insulation and other reflective material but do not understand the authors use of r-value in this article. Below is mentioned text:
"As products improve in efficiency, the R-value declines. This results
in less favorable economics, i.e. longer payback periods. As products become
more efficient, the law of diminishing returns makes it more difficult
to achieve economical efficiency gains. In other words, efficiency gains
become more expensive to achieve."

complete article can be found here
http://eds.a.ebscohost.com/eds/detail/d ... 669&db=a9h

could some clever person please clarify this for me as my understanding has hit a roadblock.
thank you,
Stewart
stewart1000
Solar Supporter
Solar Supporter
 
Posts: 2
Joined: Sat Mar 19, 2016 11:05 am

Re: R-Value and Wind Turbines - please clarify.

Postby australsolarier » Sat Mar 19, 2016 3:11 pm

i think he means the energy you put into the device compared to what it then generates. windmills have something like 400. (400 times more out than what it takes to produce)

i do not quite agree with the author though. it seems to me to more you develop things, the better the get. then again he might be talking about something different.

for some reason he uses an inverted R value.
Last edited by australsolarier on Sat Mar 19, 2016 3:55 pm, edited 1 time in total.
australsolarier
Solar Crusader
Solar Crusader
 
Posts: 521
Joined: Sun Mar 28, 2010 9:27 am

Re: R-Value and Wind Turbines - please clarify.

Postby APR » Sat Mar 19, 2016 3:51 pm

I think what he is getting at is the following.....

I have a device that produces at 50% efficiency and costs 100 units of cost.

I upgrade at some point to a unit that produces at 75% efficiency and costs 100 units of cost

A new unit comes out that produces at 80% efficiency and costs 100 units of cost. Is it worth upgrading for a 5% gain.

A new unit comes out that produces at 82% efficiency and costs 100 units of cost. Hard to justify an upgrade.

Only those with the the lower efficiency products might justify the upgrade to the latest product.

Those with the 80% efficient produce could perhaps never justify the cost to upgrade to 82% efficiency.
2 x Goodwe GW5048D-ES Hybrid inverters, 13kW panels, 20kWh LiFePO4
Mk2 PV Router feeding excess solar generation to a 3.6kW 250 ltr HWS
APR
Solar Crusader
Solar Crusader
 
Posts: 184
Joined: Sat Aug 01, 2015 3:09 pm
Location: North Coast NSW

Re: R-Value and Wind Turbines - please clarify.

Postby australsolarier » Sat Mar 19, 2016 4:00 pm

the author compares a 1980ies windmill with one of 2011.

besides it would be a bit difficult to give numerical values, to whether or not somebody wants to upgrade to a 2% more efficient device.

1) Class IV wind location,
2) Power plant efficiency, site to source = 34%
3) Fuel Price of $5/MMBtu
4) Generator Capacity is 1 MW
5) Natural Gas Power Plant Capital Cost = $665/MW

this is what he was talking about with that R-value. did you read the link?
australsolarier
Solar Crusader
Solar Crusader
 
Posts: 521
Joined: Sun Mar 28, 2010 9:27 am

Re: R-Value and Wind Turbines - please clarify.

Postby APR » Sat Mar 19, 2016 9:52 pm

australsolarier wrote:...did you read the link?


I was only able to read the abstract on my mobile device, and made a few assumptions about based upon the abstract. Seems I was wrong.
2 x Goodwe GW5048D-ES Hybrid inverters, 13kW panels, 20kWh LiFePO4
Mk2 PV Router feeding excess solar generation to a 3.6kW 250 ltr HWS
APR
Solar Crusader
Solar Crusader
 
Posts: 184
Joined: Sat Aug 01, 2015 3:09 pm
Location: North Coast NSW

Re: R-Value and Wind Turbines - please clarify.

Postby stewart1000 » Sat Mar 19, 2016 10:17 pm

thank you all very much for your input.
I now understand the r-value used in the article to be related to this article only; and that there is no relation between it and the r-value used to measure efficiency of insulation materials.

Thanks again,
Stewart
stewart1000
Solar Supporter
Solar Supporter
 
Posts: 2
Joined: Sat Mar 19, 2016 11:05 am


Return to Q&A - wind and solar power basics

Who is online

Users browsing this forum: No registered users and 2 guests

new solar power specials
cron