As stated above, PC alone during gaming can't consume so much power that it triples your electrical bill.
But to answer your question, there are 2 things you can do to reduce the power consumption of your PC:
1. Upgrade to better and more efficient GPU. Your GTX 980 Ti is 250W GPU, while for upgrade, you can go for GTX 1070 Ti (150W) which is 20% better performing or GTX 1080 (180W) which is 30% better performing than your GTX 980 Ti.
With better performing but less power consuming GPU, your PC uses less power during gaming.
2. Upgrade your PSU to highest efficiency unit, which is 80+ Titanium.
If you have e.g 650W 80+ Bronze PSU in use and let's say your PC consumes 400W during gaming and your PSU's efficiency around 50% load is 85%, your 650W 80+ Bronze PSU would draw from the wall 460W while providing 400W to your PC. The excess 60W is wasted as heat due to the PSU's low efficiency.
But if you'd have 650W 80+ Titanium PSU, which efficiency around 50% load is 94%, then your PSU would draw 424W from the wall while providing 400W to PC. With higher efficiency, only 24W would be wasted as heat.
For 80+ Titanium PSU, i suggest Seasonic PRIME 650 80+ Titanium,
pcpp:
https://pcpartpicker.com/product/nn648d/seasonic-prime-650w-80-titanium-certified-fully-modular-atx-power-supply-ssr-650td
PRIME 650 80+ Titanium is the best 650W PSU money can buy at current date and with it, you'll get the highest efficiency (94%), tightest voltage regulation (0.5%), longest hold-up time (30ms), lowest ripple noise (20mV) and longest warranty (12 years) there is. Fully modular cables and toggle-able Premium Hybrid fan control too.
specs:
https://seasonic.com/prime-titanium
review:
http://www.tomshardware.com/reviews/seasonic-prime-titanium-650w-psu,4690.html
All my 3 PCs: Skylake, Haswell and AMD are also powered by Seasonic while i have the PRIME 650 80+ Titanium unit in Skylake build. Full specs with pics in my sig.