Right next door in Utah, you are also better off with a generator.  The
'average sunlight' maps may say different, but they likely aren't
accounting for the heavy inversions that we get in these mountainous
regions.  Sometimes we don;t see the sun for two weeks or more.  Air
quality is like Beijing.

On Tue, Jun 20, 2017 at 9:34 PM, Eric Kuhnke <[email protected]> wrote:

> I have to respectfully disagree, in WA and BC the mid winter sunlight
> hours are even fewer. But 12 x 345W panels tilted at 80 degrees facing
> directly south will produce far more than enough kWh/mo for a particular
> type of site's calculated needs, in December and January. Battery voltage
> monitoring systems are set up and a portable generator can be brought to
> the site if needed during those two months.
>
> Predicted production is about 247kWh a month in December.
>
> Load, which is all DC, is below 90 kWh/mo.
>
>
>
> On Tue, Jun 20, 2017 at 8:29 PM, Sean Heskett <[email protected]> wrote:
>
>> Totally agree with Chuck on this line of thought.  Where we are (NW
>> ColoRADo) there is no amount of panels + batts you can install for Dec &
>> Jan.  Propane generator is the only way to keep an off grid site running.
>> YMMV
>>
>> -Sean
>>
>>
>>
>> On Tue, Jun 20, 2017 at 5:17 PM Chuck McCown <[email protected]> wrote:
>>
>>> Remote start propane generator is a much better value for sites like
>>> this.  In the middle of winter have a low voltage relay trigger the
>>> generator.  Run it just long enough to top the batts.  Usually an hour a
>>> day is more than enough.  Store enough propane to get through the worst of
>>> it.
>>>
>>> *From:* Eric Kuhnke
>>> *Sent:* Tuesday, June 20, 2017 6:00 PM
>>> *To:* [email protected]
>>> *Subject:* Re: [AFMUG] Vendor for super high efficiency (Sunpower,etc)
>>> PV panels
>>>
>>> I care about efficiency because in some cases space is at a premium. If
>>> these were going on the roof of a warehouse/office type building I would
>>> agree. But in a place where it is 4x4 access only, and only in summer,
>>> there is a scenario where a big ground mount tilted at 80 degrees for off
>>> grid will only hold 12 x 72-cell panels (2.0 x 1.0m each).
>>>
>>> Going any bigger than that for square footage of panels and size of
>>> mount will drive up the cost considerably. The site I am building right now
>>> has 12 x 345W 72-cell panels, and I am looking at a configuration with 12 x
>>> 360W panels for the next one. The goal is the greatest possible kWh
>>> production in December and January and additional safety margin for
>>> extended periods of cloudy days in mid winter.
>>>
>>>
>>>
>>> On Tue, Jun 20, 2017 at 6:58 AM, Chuck McCown <[email protected]> wrote:
>>>
>>>> I use 11 watts per square foot as a rule of thumb.  Never wanted
>>>> efficiency, always wanted low $/watt.
>>>>
>>>> *From:* Eric Kuhnke
>>>> *Sent:* Monday, June 19, 2017 6:47 PM
>>>> *To:* [email protected]
>>>> *Subject:* [AFMUG] Vendor for super high efficiency (Sunpower, etc) PV
>>>> panels
>>>>
>>>> Anyone have a favorite vendor source for >21% efficient PV panels
>>>> they'd like to share?
>>>>
>>>> I'm looking at various commodity 60 and 72-cell modules made with 4.95
>>>> to 5.0W high efficiency 156mm monocrystalline cells, but the Sunpower mono
>>>> stuff is still better in STC watts per square foot.
>>>>
>>>> 60-cell x 5W = 300W
>>>> 72-cell x 5W = 360W
>>>>
>>>>
>>>> Of course, willing to pay somewhat of a price premium....
>>>>
>>>
>>>
>>
>

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