The farmers, or the property owners. These solar farms are either purchasing the land for greater than agriculture prices, or signing very nice, long term leases, at significantly more than cash rent rates for ag. The power company is benefiting, mostly just by the speed/ease of increasing production. The rate payers are benefiting, even if prices dont drop, they dont increase at the same rate they would. The contractors doing the work benefit. Honestly, water quality likely improves. Not anti ag, but ag generally Does have a negative to water quality. Manufacturer benefit. Local motels, camp grounds, and restaurants benefit during construction as workers need to eat/sleep.
The closest thing to a "victim" in this, is people who just dont like looking at what other people do on their own property. Wild life, somewhat, but its not completely all bad, but it does support less than ag or woods, and different animals benefit vs ag. Water quality,.. maybe, its not dirty, actually cleaner then ag, but it also is more run off from impervious surface area. Long term, established Ag businesses (seed, fertilizer, equipment, insurance, processors, ect), do take a hit.