BETTER: Utility data with negative values generates error

[RDmitchell]

Describe the bug

I decided to test whether importing just greenbutton data would allow BETTER to do an analysis.

Expected Behavior

I imported 3 different greenbutton files, two with electric meter data (at different time periods) and one natural gas file, as the meter data for a sample building that did have BETTER results (just for electricity) when I used the ESPM sample meter data.

The 2018-2019 electric data had some negative values for the meter readings.

I then did a BETTER analysis on just that run.

Actual Behavior

There was an error message in the BETTER analysis table that I haven't seen before.

Steps to Reproduce

See this doc

https://docs.google.com/document/d/1kcUGxRMpJn0UFH3t9htFZsF6J37hQPSxQSqMmWnUHK8/edit?usp=sharing

Instance Information

Instance: dev2
SHA: 1dc9013

See the linked doc above for more information about org, etc.

Additional Context

[RDmitchell]

We might want to try to catch this problem with the data before sending it to BETTER.

Or possibly figure out how to deal with legitimate negative data, ie, from solar or other contributions to the grid ??