Update index.md (#4)

* Add more information about the project

* Add information to index.md

Project goals, incomplete link to email signup.

* Update index.md

add missing '/'

* Update index.md

Co-Authored-By: Will Holmgren <william.holmgren@gmail.com>

* Add email link, some editing

Co-authored-by: Will Holmgren <william.holmgren@gmail.com>

Author: cwhanse

index.md

@@ -6,6 +6,21 @@ layout: base
 
 The Solar Performance Insight is an open source tool to enable evaluations of solar power plant performance.
 
-See the [funding page](funding) for more information on the project's DOE SETO funding.
+[Sign up](https://solarperformanceinsight.github.io/emaillist/) to recieve project updates by email.
+
+Members of the solar community are invited to join the [Stakeholder Committee](/stakeholdercommittee) to provide guidance on project development. 
+
+# Project Goals
+
+A common task in PV Operations and Maintenance (O&M) is to compare expected system performance with actual performance
+over a period of time. Currently, O&M service engineers must adapt their workflows to the available modeling tools which
+are primarily designed to predict future performance, rather than model past performance.
+
+Our project will build a performance modeling and analytics platform based on open-source, extensible, community-maintained code. The project will benefit to the solar community through two primary outcomes:
+-	Extending [pvlib-python](https://github.com/pvlib/pvlib-python) to easily model PV systems with greater detail.
+-	Deliver modeling capabilities through a web-based dashboard and an API.
+We work directly with industry stakeholders to validate user stories, derive use cases and analytic requirements, and test the platform.
+
+# Funding
+See the [funding page](/funding) for more information on the project's funding from the U.S. Department of Energy's Solar Energy Technology Office.
 
-We continue to seek members of the solar community to provide guidance on project development. Please see our [Stakeholder Committee](/stakeholdercommittee) page for more information on how you can join the committee and help guide the project development.