Meet the SunHopper®-D
Direct-to-Tank PV Hot Water Inverter
Hot Water Efficiently
Easy Installation
Wireless Monitoring
Configurable
PV Water Heating Savings Calculator
Judge your own potential energy savings by adding solar to your hot water system. Use our easy-to-use calculator to see the SunHopper®-D advantage.
Calculate My Savings →The Hidden Energy Giant
While most homeowners focus on LED lighting or high-efficiency appliances, the water heater remains the silent giant of household consumption.
Accounting for 17% of total household energy, water heating is the second largest expense in the average American single-family home. It is often the most ignored opportunity for significant, long-term savings.
The SunHopper®-D targets this "invisible" expense directly, turning a standard utility burden into a self-sustaining asset that reduces water heating costs by 60-80%.
Intelligent Energy Scheduling
The SunHopper® algorithm intelligently schedules your energy usage, deciding exactly when to harvest Photovoltaic power and when to engage the backup grid. It optimizes for maximum PV utilization and minimum cost, even under complex Time-of-Use utility rates.
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Predictive Solar Scheduling
Gathers local weather patterns and learns high-shading periods to maximize solar usage before household demand peaks.
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TOU Cost Intelligence
Reviews Time-of-Use utility rates to ensure any necessary electrical supplements occur during the most cost-effective windows.
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Intelligent Grid Bridge
Automatically supplements solar with grid power only when necessary, avoiding peak utility rates while ensuring hot water availability.
Service Note: SunHopper® Subscription
The SunHopper® subscription covers GreenPWR's essential cloud infrastructure, weather forecasting data, and the continuous algorithm improvements that optimize your savings.
All SunHopper®-D units include 1 year of SunHopper® Cloud service ($10/year thereafter), and we guarantee a maximum rate increase of no more than 5% per year. Monitoring and device control does not require a subscription. See Terms of Service for details.
Grid-Independent Solar Heating
One of the biggest bottlenecks in traditional solar is the utility red tape. Interconnection agreements and net-metering approvals can delay projects by months. The SunHopper®-D is designed to be a non-exporting system, meaning your solar power never goes back to the grid.
Skip the Wait
Avoid the long wait times for utility interconnection permits. Install and enjoy savings immediately.
Avoid Low Sell-Back
Utility export rates are often a fraction of what you pay for power. Using your own solar energy to heat water is 4-5x more valuable than selling it back to the grid at wholesale prices.
Grid Independent
Works seamlessly even during grid outages, ensuring you still have hot water when you need it most.
Increasing Solar Self-Consumption with Thermal Storage
Even if your roof is already covered in panels, a dedicated SunHopper®-D system provides values that grid-tie systems simply cannot match.
Variable Power Control
Standard water heaters are designed for rapid heating using binary on/off thermostats at high kW loads, usually forcing a grid draw. During MPPT action, the SunHopper®-D varies output power to maximize panel harvest, gradually heating the tank throughout the day and avoiding high-load spikes.
The SunHopper® Solution
By heating water directly from PV during the day, you use "thermal storage" as a battery. This preserves your expensive chemical battery cycles for the lights and fridge at night.
The Better Way to Heat
Maximize your ROI by using energy where it's generated.
SunHopper®-D Installation Requirements
To ensure optimal safety and comfort, specific system components are required for a complete SunHopper®-D integration:
- SunHopper®-D Unit
- PV Solar Panels (see our Energy Calculator to determine quantity)
- Rapid Shutdown System (if required by local code)
- Thermostatic Mixing Valve
- Standard electric immersion water heater (without smart controls)
Mixing Valve Recommendation
We recommend the installation of a high-quality mixing valve unless the system is exclusively meant for sink fixtures or the user does not mind natural temperature variations. Solar-heated water will vary in temperature based on sunlight intensity; a mixing valve ensures safety and consistent delivery temperatures across your household by blending hot output with cold supply water. Our SunHopper® algorithm requires a mixing valve to function properly.
GreenPWR App
Why Choose PV Water Heating over Traditional Solar Thermal?
For decades, solar water heating was synonymous with "Solar Thermal" systems: a plumbing-heavy approach involving glass tubes, copper pipes, and circulating fluids. While these legacy systems proved that the sun could indeed heat a home's water, they brought with them inherent headaches: leaks, pump failures, and high-stakes maintenance.
Today, the rapid increase in photovoltaic (PV) efficiency has enabled a cleaner, more reliable alternative. By replacing complex plumbing with simple wiring and solid-state power management, we’ve eliminated the failure points of the past.
The SunHopper®-D eliminates the mechanical burden of overheating through intelligent electronic curtailment. There is no fluid to boil, no glycol to degrade, and no mechanical stress on your plumbing: just elegant, automated energy management.
Thermosyphon (passive thermal) systems can be a very good and low-cost solution if the local climate is mild and the installation allows for a heavy water tank to be mounted securely on the roof. For everyone else, the SunHopper®-D provides the same solar benefits without the structural or plumbing constraints.
| Feature | Thermosyphon (Passive Thermal) | Traditional Active (Forced Thermal) | SunHopper®-D (PV Direct-to-Tank) |
|---|---|---|---|
| Primary Technology | Gravity-fed Potable Water | Pumped Glycol/Hydronic Loop | Solid-State DC-to-Thermal |
| Grid Integration | Manual: Dumb thermostat backup | Fragmented: Often clashing systems | Intelligent: Predictive AC-backup algorithms |
| Tank Compatibility | Specialty: Integrated rooftop vessel | Specialty: Dual-coil heat exchanger tank | Universal: Standard electric water heater |
| Heating Element | Proprietary internal coil | External heat exchanger / Coil | Off-the-shelf immersion elements |
| Reliability | Moderate: Risk of freeze/burst | Low: Multiple mechanical failure points | Extreme: Solid-state; No moving parts |
| Freeze Protection | None: Potential for pipe bursts | Moderate: Relies on chemical antifreeze | Intrinsic: Electricity cannot freeze |
| Overheat Management | Manual/Passive: High stagnation risk | Mechanical: Requires "Heat Dumps" | Electronic: Instant Curtailment |
| Maintenance Needs | Scale removal / Tank flushing | Glycol testing / Pump replacement | Zero: Set-and-forget |
How does a PV hot water system operate?
High-Efficiency Inversion
The SunHopper®-D uses raw DC power from sunlight and converts it into a pure sine wave AC output directly at the tank. This provides the exact waveform your standard immersion heating elements were designed for, maximizing hardware longevity.
Adaptive MPPT Action
Our algorithm finds the maximum power point no matter the weather, shading, or exact panel conditions. By dynamically adjusting the load and matching impedance in real-time, we ensure absolute maximum harvest at every moment.
Intelligent Grid Bridge
For total reliability, the system manages the bridge between solar and AC grid power when using electricty as the backup source. Utility backup is optimised preventing unnecessary costs and maximizing your household's solar fraction.
Heat-Pump vs SunHopper®-D
| Feature | Heat Pump (HPWH) | SunHopper®-D |
|---|---|---|
| Core Technology | Active Refrigerant / Compressor | Passive Resistive (Solid State) |
| Moving Parts | Fan, Compressor, Pumps | Zero |
| Noise | Compressor and fan noise | Silent |
| Reliability | Moderate: Mechanical wear | Extreme: No moving parts |
| Cold Performance | Efficiency drops significantly | Efficiency increases in the cold |
| Maintenance | Filters & Condensate drains | Zero |
Unlike a heat pump water heater (HPWH) which relies on a mechanical compressor and refrigerant cycles prone to wear, a SunHopper®-D system has zero moving parts. This "Direct-to-Tank" solution leverages the inherent durability of standard solar panels built to withstand decades of sun.
Traditional hybrid heat pumps cooling your air can create a "thermal tug-of-war" with your furnace in winter. The SunHopper® thrives in the cold, where PV efficiency actually increases, delivering peak performance precisely when household demand is highest.
Storm Performance
Unlike standard grid-tie systems that shut down during power outages, the SunHopper®-D is a DC-coupled architecture that prioritizes your independence.
Grid-Independent Harvest: Because your PV array connects directly to the SunHopper® unit, the system continues to heat your water during day-time grid failures. While the rest of the neighborhood waits for the grid to return, your thermal battery keeps charging securely from the sun.
Technical Specifications
Built for durability, efficiency, and safety.
Solar Input
Grid Input
Supported Heaters
Safety Features
Connectivity
Environment & Warranty
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