They can help you run the numbers and often even know the scoop about tax incentives (which is why it is worth running the numbers even though the technology may be getting cheaper -- when it does, there may not be as good tax breaks.)
This list here:
http://energy.sourceguides.com/businesses/byGeo/US/byS/IN/byP/solar/solar.shtmlLists a couple consulting companies in Indiana (the rest of the companies seem to be retail/export):
Morton Energy, LLC
* Business type: Renewable Energy Products and Services
* Product types: Solar PV systems, wind-powered turbines, solar hot water, solar pool heating, solar golf carts, solar construction trailers and more..
* Service types: consulting, design, installation, project development services, site survey and assessment services, contractor services
* Address: 4620 Weaver Road, Evansville, Indiana USA 47711
* Telephone: 812-490-3600
* FAX: 812-402-9695
SAVER
* Business type: retail sales, wholesale supplier, exporter
* Product types: solar system packages,advanced power systems, solar electric power systems, photovoltaic systems, generators, renewable energy system batteries, wind energy systems (small), DC to AC power inverters, water filteration & conditioning, energy saving refrigeration, energy saving washer & dryers, hybrid power stations.
* Service types: retail sales,consulting, engineering design, project development services, financial services
* Address: 350 Woodland Trail Drive, Indianapolis, Indiana USA 46239
* Telephone: 317-465-8496
* FAX: 317-465-8496 press 2