Every energy rental platform quotes prices in SUN — not TRX. But what is a SUN, how is it set, and why does a 65k energy rental cost 3.00 TRX on one site and 9.00 on another?
What is a SUN?
SUN is TRON's smallest unit — 1 TRX = 1,000,000 SUN. Named after Justin Sun, it's the atomic denomination used for all on-chain calculations. When you rent energy, you're not paying "2.34 TRX" — you're paying 2,340,000 SUN. The platform expresses this as a SUN rate: the number of SUN charged per unit of energy.
The pricing formula is:
Price in TRX = (Energy Amount × SUN Rate) / 1,000,000
Example: A platform charges 36 SUN for 65,000 energy. That's 65,000 × 36 / 1,000,000 = 2.34 TRX. If the SUN rate moves to 42, the same rental costs 2.73 TRX. A 6-SUN shift changes your price by nearly 17%.
How platforms set their SUN rates
There's no central SUN rate. Each platform sets its own based on three factors:
1. Energy pool utilization
Every platform has a finite energy pool — the total energy delegated to them by stakers. When the pool is 80% utilized, rates rise. At 40%, rates fall. Some platforms like TronMax show this as a marketplace order book where you can see bid/ask spreads in real time. Fixed-rate platforms like FeeSaver and NETTS adjust rates manually, typically once a day or less.
2. TRX market price
Since energy is priced in TRX, the USD value of a rental fluctuates with TRX. When TRX pumps, platforms often lower SUN rates to keep the dollar cost competitive. When TRX dumps, SUN rates rise to maintain revenue. This creates counter-cyclical price movements: energy gets cheaper in TRX terms when TRX appreciates.
3. Competition
With 20 platforms competing, SUN rates converge toward a market equilibrium. The spread between cheapest and most expensive 65k/1h rental is typically 3-5×. CatFee, FeeSaver, and NETTS consistently lead the low-cost segment at 2.30–2.70 TRX. Premium platforms with APIs and advanced features charge 5.00–9.00 TRX.
Recent market events affecting SUN rates
TRON proposal #104 cut the base transfer fee from 5 TRX to 3 TRX, putting downward pressure on energy prices — if burning is cheaper, renting must compete harder. TronMax crossed 500k total energy delegated in May 2026, flooding the market with supply. Meanwhile, TRON hit 300M accounts and USDT supply on TRON crossed $60B — more users, more transactions, more energy demand.
Which platform model is cheapest?
Fixed-rate platforms (FeeSaver, NETTS, CatFee) offer the most predictable pricing. You know exactly what you'll pay. Marketplace platforms (TronMax, Brutus) can be cheaper during low-demand periods but spike during peaks. API-driven platforms (iTRX, Feee.io, Tronex) charge a premium for automation but offer quantity discounts at scale.
For occasional users, fixed-rate is the safest bet. For bots doing 50+ transfers/day, API platforms with volume pricing win. Check our live comparison tool to find the current best deal.