If you’ve ever dreamed of true energy independence, going off-grid is no longer out of reach. Whether you’re building a remote cabin, upgrading a cottage, or preparing for future power outages, staying comfortable without relying on the grid is now a tangible possibility. With Ecosolaris’s solar heat pump, you can enjoy reliable cooling and heating no matter where you are, completely off-grid.
The Ecosolaris solar heat pump offers the possibility to run entirely on a dedicated battery system. By storing solar energy during the day, the system can deliver 24/7 climate control without any reliance on fossil fuels or the grid when the sun sets. Whether you’re off-grid or simply want energy autonomy, the Ecosolaris heat pump’s battery-powered mode ensures complete freedom from external power sources.
Keep in mind, this article focuses on battery-powered operation and may not apply to other heat pump operation modes such as solar-only, hybrid (solar + grid), or grid only. And note that the battery could also be charged by sources other than solar power.
Unlocking True Autonomy: The Power of Battery-Powered Mode
For those evaluating off-grid solutions to cool or heat their space, it’s essential to know that Ecosolaris’s solar heat pump can be powered entirely by a battery system, where the heat pump runs solely on energy stored in a 48 V battery bank. In this mode, solar panels charge the battery throughout the day, and the heat pump pulls power exclusively from that battery bank, never from the panels directly or the grid. Each cooling or heating cycle draws from stored solar power, making the battery the core of a fully independent system.
How it Works: A Closer Look at Battery-Powered Operation
The operational synergy between the solar heat pump and its battery system is very smart. Here’s a breakdown of the process that ensures comfort, 24/7:
1) Capturing Solar Power
Solar Array
- A solar array, totaling anywhere between 2000 W - 4000 W, depending on the battery’s storage capacity and the heat pump’s BTU rating, converts sunlight into DC electricity.
- These panels feed into a photovoltaic DC disconnect switch (installed for maintenance and safety) before reaching the MPPT solar charge controller.
MPPT Solar Charge Controller (Maximum Power Point Tracking)
- A solar charge controller gathers energy from your solar array, and stores it in your battery.The MPPT constantly adjusts its operating point to extract maximum power from the panels.
- When your heat pump’s demand is low or nonexistent, the MPPT continues to direct all solar power into the 48V battery, charging it efficiently while still supplying any active load from the battery.
2) Storing Energy in a 48 V Battery Bank
Purpose of the Battery
- The 48V battery stores solar power, which is then used to run the heat pump. Because all the energy must first pass through the battery, this setup requires more solar power, and thus more solar panels.
- The battery delivers stable energy at all times and whenever PV output dips, cloud cover, dusk, or overnight operation.
Charging Logic
- Since all solar power flows through the battery, the MPPT continuously charges it whenever there’s sufficient PV voltage and current, regardless of the heat pump’s demand. The battery should reach a sufficient charge level before it can power the heat pump.
- This process continues until the battery reaches its full-charge voltage (typically around 54 V for a 48 V bank).
3) Battery as the Sole Power Source
The heat pump always draws power from the battery, there is no direct feed from the panels to the compressor. Here’s how it works:
Continuous Battery Power
- The MPPT charge controller sends all solar production into the 48 V battery bank.
- The heat pump’s compressor and controls draw exclusively from the battery, never directly from the panels.
Low Battery Protect Device
- If the battery voltage drops near a critical low, a low battery protection device is installed to preserve battery health.
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Based on the set threshold, the low battery protection device automatically disconnects all loads to prevent deep discharge, protecting the battery and ensuring enough power remains to start the heat pump.
4) Boosting Voltage for the Compressor
The DC compressor in Ecosolaris solar heat pumps runs on roughly 240 V DC. The 48 V battery alone cannot supply this natively, so we employ a DC Booster (DC-DC converter):
DC Booster (DC 48 V → DC 80–350 V)
- Converts 48 V from the battery up to the precise voltage the compressor electronics need at any stage of operation, whether starting up or running at peak performance
- Provides a continuous, stable high-voltage DC feed, even as the battery’s voltage slowly drops during discharge.
Instantaneous Power Delivery
- Whenever the heat pump calls for cooling or heating, the DC Booster draws solely from the battery, there is no fallback to panel-direct.
- Because the battery is always charged first by the panels, the booster can respond in real time without any delay or interruption to compressor operation.
5) Protecting the Heat Pump: Surge & Breaker Switch
Before the boosted voltage reaches the outdoor unit, it should pass through a combined DC Surge & Breaker switch:
DC Surge Protection
- It guards the compressor electronics against voltage spikes, whether from lightning or sudden transients.
DC Breaker
- It allows a manual disconnect for maintenance or emergency shutdown.
- It ensures that if any fault is detected (overcurrent, short circuit), the circuit trips before damage can occur to the heat pump.
6) Powering the solar heat pump
- The heat pump’s DC compressor runs directly on DC power from the battery, avoiding any AC conversion losses and making the compressor highly efficient for battery-powered systems.
- The heat pump pulls all its energy from the battery (even if the battery is being topped up simultaneously). Because the heat pump never runs directly off the panels, there is no “mode switching” from panel to battery. The battery is always the single source for the heat pump.
In summary:
- Solar panels produce DC power.
- The MPPT controller charges the 48 V battery.
- The DC booster raises the battery voltage to what the compressor electronics need.
- The heat pump’s DC-DC compressor runs directly off the battery.
- Electrical protections ensure your solar system, battery, and heat pump are all safely protected.
What You Need to Know: Essential Considerations
Before selecting equipment, consider your daily cooling and heating loads, the number of consecutive cloudy days you want to cover, and the total budget you can allocate. Undersizing any one piece, solar panels, batteries, or protective devices, risks unexpected downtime, shorter battery life, or underperformance.
Solar Array Sizing: Why Battery Systems Require More Panels
In battery-powered mode, all solar energy flows into the battery bank, there’s no direct connection between the panels and the heat pump. Since the heat pump draws energy exclusively from the battery, 24/7, your solar array must be sized to:
- Power the heat pump during the day while simultaneously charging the battery, and
- Store enough energy for operation at night, during dusk, or through extended cloudy periods.
Matching Panel Output to BTU Demand
The 12,000 BTU Ecosolaris heat pump consumes approximately 900 W, while the 18,000 BTU unit draws around 1.3 kW in both heating and cooling modes. Naturally, higher BTU systems will require a larger PV array to meet their energy demand.
Larger Battery Bank = Larger PV Array
For instance, charging and maintaining a 48 V 10 kWh battery will require significantly more solar input than a 5 kWh bank. The bigger the storage, the more wattage your array must consistently deliver.
Geographic Factors Also Matter
The exact number of solar panels, or total solar wattage required, will also depend on factors such as geographic location and solar exposure.
Battery Bank Sizing
The size of your battery bank directly impacts how long your system can operate without sun. You need to opt for a battery size that fits your needs. Below are typical 48 V configurations with estimated runtimes based on average compressor consumption.
Keep in mind: Even when the heat pump is running, the compressor isn’t constantly drawing power. It activates to reach the set temperature, then cycles off while the fan maintains the room, drawing minimal energy. So, the runtimes below (in hour) refer specifically to compressor runtime, not total system uptime.
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48 V 100 Ah → 5.12 kWh
- Provides about 8-12 hours of compressor runtime. Suitable for short stays or situations where cooling/heating isn’t needed continuously.
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48 V 200 Ah → 10 kWh
- Covers around 12-18 hours of compressor runtime. Ideal for weekend cabins or areas with inconsistent solar input.
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48 V 300 Ah → 15.36 kWh
- Delivers approximately 18-24 hours of compressor runtime. Well-suited for full-time off-grid use or longer periods when sun is absent.
Why Choose Lithium Battery?
Lithium-ion batteries are great batteries to use because you can safely use up to 90 % of their capacity, they endure 2 000-5 000 cycles, and they deliver the high discharge currents needed for compressor startups. Just remember that most lithium batteries won’t charge below 0 °C and shouldn’t be stored below -20 °C or above 60 °C, which is the reason why indoor installations are encouraged.
Protect the System
Maintaining reliable off-grid operation starts with safeguarding every component against common risks.
Batteries can suffer permanent damage if deeply drained, so incorporating a means to disconnect all loads before voltage drops too far is crucial for preserving capacity.
Likewise, solar arrays are vulnerable to wiring faults, lightning strikes, or sudden voltage surges, ungrounded or unfused strings can cause costly failures. Ensuring you have over-current protection and a clear way to isolate the battery bank keeps small issues from cascading into full system downtime.
Protecting the heat pump itself is equally important: install appropriate surge protectors and breakers on its power input so you can safely shut it down if an electrical fault or overload occurs.
Don’t Overlook the Full Deployment Cost
Installing a fully off-grid, battery-powered solar heat pump system involves more than just buying the battery. Once you factor in all components and installation, the total investment typically ranges from $10,000 to $15,000 CAD.
That said, the up-front cost brings long-term benefits. You eliminate monthly electricity bills, avoid rising utility rates, and gain resilience against power outages. In remote areas, cold-climate regions, or locations with high utility rates, payback can be achieved in as little as 5-10 years. For those seeking true energy independence, the long-term return more than justifies the initial expense.
Conclusion
Achieving true energy independence with a solar heat pump powered by a dedicated battery system transforms how you experience comfort, wherever you are. This guide has illuminated the intricate yet intelligent synergy between solar panels, battery banks, and the heat pump itself, demonstrating how stored solar energy can deliver reliable cooling and heating 24/7, completely free from the grid.
From understanding the critical role of the 48V battery and the DC Booster to carefully sizing your solar array and battery bank, every component plays a vital part in ensuring seamless off-grid operation. We've highlighted the importance of robust protection devices to safeguard your investment and outlined the comprehensive costs involved, emphasizing that the initial outlay translates into invaluable long-term savings, resilience, and unparalleled energy autonomy.
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