Does your jurisdiction have time of use billing? What are your local laws about solar buy back?
With that much acreage and usage, a solar setup might pay itself back pretty quickly. You can consider either just doing a standard grid tie setup where you sell power back to the grid, or use batteries to timeshift your generation and usage curves, or maybe even put parts of the operation off-grid altogether (with battery and generator backup). If she has a river or stream nearby, microhydro might be a possibility too.
You can get a processional energy audit done, or if you're the DIY type, sometimes you can loan the tools (solar measurement tools, thermal cameras, energy meters, etc.) from your utility or some local energy nonprofit and learn to use them from YouTube.
If you can describe her situation in more detail, I'd be happy to discuss some options. Not an expert, but went to school for this stuff and worked in renewables for a while.