top of page

Green Hot Water: Solar Thermal Meets Heat Pump Innovation

Updated: Jul 9

a 3D solar thermal and heat pump
Heat Pump and solar Thermal Design

As cities across the U.S. increasingly ban natural gas in new buildings to reduce greenhouse gas emissions, architects and developers are encountering a series of challenges. One significant hurdle is heating large quantities of domestic hot water using electricity alone. This task is not only energy-intensive but also places considerable strain on the already struggling electrical grid.

Many cities' electrical infrastructures are not yet capable of handling the increased load from an all-electric system, further complicating the transition. This is particularly problematic in regions with older grids that require significant upgrades to support the additional demand from heating, cooking, and hot water systems, or regions where the utilities are struggling as is to cover current demand not to mention the increase in electrical loads due to increased demand for electricity.

The Challenge of Heating Domestic Hot Water

Heating water is inherently energy-intensive. Traditional methods using natural gas are being phased out, leaving electricity as the primary alternative. Heat pumps, which have an average coefficient of performance (COP) of 4, offer a more efficient solution. This means that for every kilowatt-hour (kWh) of electricity consumed, the heat pump produces 4 kWh of heat. Despite their efficiency, maintaining large storage tanks at the required 140°F is costly and places a heavy demand on the already struggling electrical grid.

Innovative Solutions: Hybrid System combining Solar Thermal and Heat Pumps

The industry is in desperate need of innovative technologies to bridge the gap left by the natural gas ban. One promising solution is the integration of solar thermal systems with heat pumps. Maktinta Energy has demonstrated that this combination can significantly reduce energy demand by 80%, providing a practical and green solution to architects and developers.

How It Works

A solar thermal system harnesses the sun's energy to heat water, which can meet up to 75% of a building's hot water needs. Solar collectors absorb solar radiation and transfer the heat to water, which is stored in insulated tanks. This system is 80% efficient in absorbing solar heat and works efficiently during sunny periods, providing a renewable and cost-effective source of hot water.

However, integrating a solar system that is 80% efficient in harvesting solar energy but slow to raise the storage tank temperature with a heat pumps, designed to quickly raise the storage tank temperature creates a conflict, where the heat pump will bring the storage tank to temperature leaving no “space” for the slower but much more efficient solar system to heat the tank. The key is to control and integrate both systems effectively to maximize efficiency and minimize costs.

Overcoming Integration Challenges with Smart Controls

Maktinta Energy has solved the integration challenge by adding a port to the solar controller to manage the heat pump operation. Our proprietary software orchestrates the solar and heat pump operations, ensuring that the systems work together seamlessly.

The software prioritizes solar gain, using solar energy to heat the water whenever possible. When solar energy is insufficient—during cloudy days or periods of high demand—the heat pump activates to raise the water temperature quickly. This approach minimizes electricity demand while maximizing the use of renewable solar energy.

Benefits of the Hybrid System

  1. Energy Efficiency: Solar thermal systems significantly reduce the electricity required for heating water, decreasing the overall energy consumption.

  2. Cost Savings: By leveraging solar energy, buildings reduce their electricity bills. The initial investment in solar technology is offset by long-term savings on energy costs and generous Government rebates.

  3. Grid Reliability: Reducing the demand on the electrical grid helps prevent overloads and increases the stability of the power supply, particularly during peak usage times.

  4. Environmental Impact: Using solar energy reduces greenhouse gas emissions, contributing to the fight against climate change and helping cities meet their sustainability goals.

  5. Scalability: This system can be scaled to fit various building sizes and types, from residential multifamily homes to large commercial complexes.


The combination of solar thermal systems with heat pumps offers a viable and sustainable solution to the challenges posed by natural gas bans in new buildings. By integrating these technologies and utilizing smart controls, architects and developers can create efficient, cost-effective, and environmentally friendly hot water systems. This innovative approach not only addresses current energy challenges but also paves the way for a cleaner, greener future in building design and construction.

If you have any questions or suggestions, please don't hesitate to contact Gal Moyal, the CEO of Maktinta Energy, at

9 views0 comments


bottom of page