# Cost vs Efficiency for same size panel
**URL:** https://forum.cleanenergyreviews.info/t/cost-vs-efficiency-for-same-size-panel/1751
**Category:** Solar Questions and Comments
**Created:** [March 7, 2021, 7:19am UTC](https://forum.cleanenergyreviews.info/t/cost-vs-efficiency-for-same-size-panel/1751 "2021-03-07T07:19:10Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@hmfossati](https://forum.cleanenergyreviews.info/u/hmfossati)
#### Post date: [March 7, 2021, 7:19am UTC](https://forum.cleanenergyreviews.info/t/cost-vs-efficiency-for-same-size-panel/1751/1 "2021-03-07T07:19:10Z")
The blog states:
**For Example,** a high efficiency 360W+ panel could cost $300 or more while a common 300W panel will typically cost closer to $150. This equates to roughly $0.50 per Watt compared to $0.90 per Watt. Although in the case the leading manufacturers such as **LG, Sunpower** and **REC** the more expensive panels have higher performance, lower degradation rates and generally come with a longer ‘manufacturer’ warranty period, so it is often a wise investment.
If I have enough roof space…
And I spend $300, I can get either:
1 of the high efficiency 360W panels, for a total of 360W output, or
2 of the standard efficiency 300W panels, for a total of 600W output
After 25 years, the 360W panel may output 330W, while the 300W panels may output just 240W for a total of 480W for the two.
So, it would seem it is a better deal to buy the cheaper (less efficient panels)…
For the same $$ amount, I generate more output power even after 25yrs.
I am thinking the panel companies are heavily discounting their older production panels and charging a premium for the newer more efficient panels.
Unless I do not have the roof space, it would seem the “lower $/W panel” is a better choice as long as I still generate more power out of them at the 25 year mark… That is, premium is only justified when roof space is not enough.
Am I doing the math wrong somewhere? Any other costs to take into account (I figure I need to buy extra micro-inverters, if that is the setup I am going for)…
Comments?
---
### Author:  [@Marty](https://forum.cleanenergyreviews.info/u/Marty)
#### Post date: [March 11, 2021, 12:56am UTC](https://forum.cleanenergyreviews.info/t/cost-vs-efficiency-for-same-size-panel/1751/2 "2021-03-11T00:56:26Z")
Hi Humberto
You’re not doing the maths wrong, and I think it is a good way to look at it.
However, another way to look at it is that for a 6.6kW system, you can pay $2500 extra and get the latest and greatest panel technology with a lower degradation rate and longer warranty. People are often very happy to pay that premium for a product that is going to be on their roof for hopefully 25 + years.
There is no right or wrong answer when choosing solar products, just as there isn’t when choosing a phone, or car. It comes down to personal preference, budget, risk appetite etc etc.
Thanks for adding to the conversation. Some good thoughts.
Cheers
Marty
---
### Author:  [@7hillstreet](https://forum.cleanenergyreviews.info/u/7hillstreet)
#### Post date: [April 5, 2021, 3:04pm UTC](https://forum.cleanenergyreviews.info/t/cost-vs-efficiency-for-same-size-panel/1751/3 "2021-04-05T15:04:29Z")
why does sunpower offer me a 10kwp system at 87% of my power with 30 panels and rec offers a 10 kw system with 100% of my power with 27 panels