Creating TMY files for India and Uploading in SAM

[Amit Jain (Clinton Foundation)]

I have two questions. Attachments have been send in a separate mail.


A. Creation of TMY3 file for Jodhpur, India
1. TMY3 creator
2. Obtain all the values from EPW file (SAM TMY3 creator data created
from IND Jodhpur.423390 ISHARE.epw file attached)
3. Copy the header including lat long etc
4. Does not create a TMY3
5. It requires an existing TMY3
6. If we use a template of TMY3 from US state (CA Blythe file
attached), there are too many columns which cannot be populated from
EPW files

Question: how can we create a TMY3 file for India

B. Using Jodhpur, India Meteronom TM2 files in SAM
1. Using Meteronom software created a TM2 file for Jodhpur, India
(IN_Jodhpur file attached)
2. Attached to the SAM by using climate tabs
3. Lat lon showing invalid options and no data is shown in the DView
4. I checked the header and compared with the standard TM2 files and
it is correct. (http://rredc.nrel.gov/solar/pubs/tmy2/tab3-1.html)

Question: Why SAM is not uploading the TM2 file from Meteronom? What
is the problem with the Meteronom TM2 file?

Thanks for your help

Amit Jain

[alberto cuellar]

1) I have realized that some of the EPW files for India (that come
from ISHRAE) have frequently DNI values above 1367W/m2 which is
supposed to be the max limit (extraterrestrial radiation). I found
this situation several times and Im quite skeptical about the quality
of these data now. I would not trust a file where during a
considerable % of the year the DNI exceeds the physical limit.

2) I have also used Meteonorm file from India and i found that the
temperature distribution does not match the theoretical behavior
associated with the monsoon. It looks like a typical european
distribution with the maximum in July/ August when due to the monsoon
the max should be achieved before that months, around May.

Im having a lot of problems to find good solar resource data for
India. Can anyone comment on my points and propose any good source for
solar radiation in India

Thanks

On Feb 24, 7:24 am, "Amit Jain (Clinton Foundation)"

[Paul Gilman]

Dear Amit,

Question A:

Using SAM's TMY3 creator involves three overall steps:

1. Open an existing TMY3 file (.csv extension) to use as a base file.

2. Copy and paste columns of 8,760 data sets into the table in the
TMY3 Creator window. You must have data for each of the columns in the
table.

3. Save the data in the table as a new TMY3 file.

The TMY3 Creator replaces the data in the base file with data from the
table in the TMY3 Creator window. Since SAM doesn't use data in the
other columns of the base file, it doesn't matter what file use use as
the base file.

Question B:

I have heard from other people who have had trouble running TMY2 files
created by Meteonorm in SAM. I haven't been able to determine what is
causing the problem, but perhaps someone else can help?

Please send me your files using the SAM support email address (solar
dot advisor dot support at nrel dot gov).

Best regards,
Paul.


On Feb 23, 10:24 pm, "Amit Jain (Clinton Foundation)"

[Chris_Gueymard]

I'm not surprised by your findings regarding the ISHRAE TMY files.
Most users (including me) have found that the measured radiation data
in India had various kinds of problems. The older data (of the '70s
and '80s) should be of much better quality because dedicated
scientists (particularly the late Anna Mani) were taking care of the
measurements. However, older data does not provide all the answers
because the resource is decreasing in India, particularly that for
concentrators, due to increasing pollution, etc.

Finding "good solar resource for India" is on every developer's mind
these days. Here's a list of things you can do:
- Install your own weather station(s). It's a costly proposition, and
will not provide you with historical data. But if you are in charge of
a major CSP or PV project, this would be the way to go if you need
bankable data. After about 12 months, the measured dataset can be used
as an input to sophisticated meteorological techniques to correct long-
term satellite-derived modeled data. That is the only acceptable way
of getting accurate time series of DNI to build your financial
projections and get financed. (Remember that TMYs are absolutely not
good for that; they should only be used for preliminary design!) The
correction process mentioned above can be done by only a few
companies, such as ours, that have the know-how.

- Use recent freely available modeled datasets, such as NREL's, with
the caveat that they are not validated yet and are only available for
a few years.

- Use commercially available modeled datasets (we can help with that).
They span about 12 years, but have been only partially validated...

- Use commercially available TMY files based on 30-year reanalysis
(meteorological) modeling (contact us).

Good luck,
Chris

[Weather Analytics]

Chris is correct that TMY files have their limits but they can be
useful in site selection and preliminary design. We have just
announced a new service that can provide a full 30 year TMY file (in
TM2 and EPW format) every 35-km across the globe (about 10,000 sites
in India). We have leveraged a new NOAA released dataset to position
over 600,000 virtual weather stations around the world with a new web-
based access system to make it accessible for users. To augment the
TMY files you can also request any or all of the individual years
(1980 - 2009) in TM2 or EPW format to model Actual Meteorological
Years and extreme actual conditions at any site. Let me know if you
want a copy of the paper we are presenting at ASES describing our
approach including output validation. More details and demo access to
the system can be found at weatheranalytics.com/
buildingmodeling.html.

When you are ready to go beyond a TMY and conduct a full analysis
described by Chris above we can provide the 31 years of hourly data
and assistance with experts like Chris to combine this with the onsite
observations.

Chuck
Principal, Weather Analytics

On Mar 2, 1:17 pm, Chris_Gueymard <ch...@solarconsultingservices.com>
wrote:

> > > Amit Jain- Hide quoted text -
>
> - Show quoted text -

[QuasiPhoto]

I'd like a copy of the paper you are presenting at ASES.

On Mar 16, 8:03 am, Weather Analytics <virtualweat...@gmail.com>
wrote: