ᐅ Heat Pump with Photovoltaic System vs. Gas Heating and Solar Thermal Energy
Created on: 7 Jun 2016 21:53
I
inconel
Hello everyone,
for my house construction, which will start next year, I would like to gather information about the heating system, specifically regarding the two options:
+ Gas condensing boiler, supported by approximately 12m² (130 sq ft) of solar thermal panels and a wood stove
+ Groundwater heat pump powered by a photovoltaic system
About the property:
+ Planned is a 10x11m (33x36 ft) house with two full floors, a basement, a hip roof with about 35m² (375 sq ft) of south-facing roof area, and approximately 200m² (2,150 sq ft) of living space.
+ Exterior walls made of 36.5cm (14 inches) perlite-filled bricks “Poroton T7”
+ Location: Bavaria, with an average annual solar radiation of about 1000 kWh/m²
Option 1: Gas condensing boiler
Advantages:
- Proven, durable gas condensing technology (efficient)
- Fast response time of the gas heating system, requires no long preheating
- From around April to October, the thermal energy from the solar panels is sufficient (no gas needed); in winter, supported by the wood stove for both hot water and heating
Disadvantages:
- Solar panels need to be cooled relatively early in summer, meaning little hot water is required but excess heat must be dissipated from the panels → increased electricity and water costs without added benefit
- Large domestic hot water storage tank needed to utilize countercyclical heating periods
Option 2: Photovoltaics with heat pump
Advantages:
- Autonomous heat and electricity production
- “Green energy”
- Additional support for other continuous electricity consumers (refrigerator, freezer, washing machine, dryer)
- Relatively low effort to install suction and discharge wells, as groundwater is already available at about 2.5m (8 ft) depth
Disadvantages:
- High investment costs for both photovoltaic system and heat pump (long payback period)
- Limited sunshine during months with high energy demand
- Complex and expensive, but still necessary, storage solutions for photovoltaic electricity
I hope you can understand my concerns and ideas, and I would really appreciate your feedback. How do you see the situation? What do you think is truly practical?
Thank you very much
Best regards
for my house construction, which will start next year, I would like to gather information about the heating system, specifically regarding the two options:
+ Gas condensing boiler, supported by approximately 12m² (130 sq ft) of solar thermal panels and a wood stove
+ Groundwater heat pump powered by a photovoltaic system
About the property:
+ Planned is a 10x11m (33x36 ft) house with two full floors, a basement, a hip roof with about 35m² (375 sq ft) of south-facing roof area, and approximately 200m² (2,150 sq ft) of living space.
+ Exterior walls made of 36.5cm (14 inches) perlite-filled bricks “Poroton T7”
+ Location: Bavaria, with an average annual solar radiation of about 1000 kWh/m²
Option 1: Gas condensing boiler
Advantages:
- Proven, durable gas condensing technology (efficient)
- Fast response time of the gas heating system, requires no long preheating
- From around April to October, the thermal energy from the solar panels is sufficient (no gas needed); in winter, supported by the wood stove for both hot water and heating
Disadvantages:
- Solar panels need to be cooled relatively early in summer, meaning little hot water is required but excess heat must be dissipated from the panels → increased electricity and water costs without added benefit
- Large domestic hot water storage tank needed to utilize countercyclical heating periods
Option 2: Photovoltaics with heat pump
Advantages:
- Autonomous heat and electricity production
- “Green energy”
- Additional support for other continuous electricity consumers (refrigerator, freezer, washing machine, dryer)
- Relatively low effort to install suction and discharge wells, as groundwater is already available at about 2.5m (8 ft) depth
Disadvantages:
- High investment costs for both photovoltaic system and heat pump (long payback period)
- Limited sunshine during months with high energy demand
- Complex and expensive, but still necessary, storage solutions for photovoltaic electricity
I hope you can understand my concerns and ideas, and I would really appreciate your feedback. How do you see the situation? What do you think is truly practical?
Thank you very much
Best regards
Eigenheimler19 Jun 2016 11:50If I’m not mistaken, the current feed-in tariff for electricity generated by photovoltaic systems is significantly lower than it was when these systems were first introduced. I doubt that the tariff will increase along with rising electricity prices; it will more likely go in the opposite direction!
If electricity prices really increase, the feed-in tariff will also go up.
However, in recent years, the cost of electricity has not actually risen significantly; only taxes and levies have been increased. For the past 4 years, the electricity price for end consumers has remained almost steady.
However, in recent years, the cost of electricity has not actually risen significantly; only taxes and levies have been increased. For the past 4 years, the electricity price for end consumers has remained almost steady.
B
Bauexperte19 Jun 2016 12:40@Sarrus: Your statement is a bit simplistic... How many people live with you, and how much area do you need to heat? Basically, you can say that a heat pump with an average COP of 3 requires about 10 cents of pure consumption energy per 1 kW of heat, excluding investment costs. If there are three of you and each showers for 5 minutes every day, your €300 electricity cost is already gone. Heating is not included, and heat loss is also not considered.
Tom1607 schrieb:
@Sarrus: Your statement is a bit exaggerated ….. How many people live with you, how much space do you need to heat …. Basically, you can say a heat pump with an average COP of 3 requires about 10 cents of pure consumption energy for 1 kW of heat without investment costs. If there are 3 of you and each showers 5 minutes every day, your 300€ electricity is already gone. Heating isn’t even included, and neither is waste heat loss. Your statements are very exaggerated. There are also no justifications or calculations (e.g., I won’t recover my investment in 30 years… 9% return… I would always use solar thermal etc.). So maybe you should look at yourself first. By the way, you can find all the details about my "build" here in the forum (I have detailed all construction costs etc.) and in a post about heat pump experience, you can also find some information about my usage. Aside from that, energy is measured in kWh, not kW as you mentioned above.
Your example with showering costs me a maximum of 500 kWh of electricity with the heat pump, which is about 100 euros. That is quite far from the 300 euros you mentioned. And with a COP of 3, one kWh of heat from the heat pump costs 6.6 cents, which is about 35% less than what you said, based on current prices.
So, take a look at yourself and next time respond with less exaggeration.
I have now taken a look at your thread ... nice house.
You mention a consumption of 2000 kWh, which for me would mean around €600 heating and hot water costs, contrary to the €300 you stated.
The 9% return is easy to explain. I have an installed capacity of 30 kW peak. The system cost €57,000 net and generated a net income of €5,465 in 2015 (I have not considered taxes or depreciation here).
In 2015, I consumed 1,800 kWh of electricity and fed in 34,000 kWh. I receive €0.16 for the kWh fed in.
I pay €0.31 per kWh including VAT.
My building has a heated area of just over 600 m² (6,458 sq ft), which would not be efficient to heat with a heat pump. Since I have a roof area of over 400 m² (4,306 sq ft) entirely facing south, it makes sense for me to install and use solar thermal and photovoltaic systems.
My heating system (Vaillant gas condensing boiler, 2,000 l (530 gallons) buffer tank, Vaillant solar station) cost around €12,000.
This means I have about €8,000 less investment than your heating system. For that, I get around 100 rm (stere) of wood.
Regarding the wood: 1 rm (stere) of beech wood currently costs about €80. 1 rm (approximately 550 kg / 1,213 lbs) of wood corresponds to a heating output of 2,000 kWh, which results in about €0.045 per kWh.
Heating oil is around €0.50 per liter and has an energy content of 11 kWh, similar to gas.
Looking at the costs now, I do not make up the extra expenses for a heat pump, so my statement is quite accurate.
You mention a consumption of 2000 kWh, which for me would mean around €600 heating and hot water costs, contrary to the €300 you stated.
The 9% return is easy to explain. I have an installed capacity of 30 kW peak. The system cost €57,000 net and generated a net income of €5,465 in 2015 (I have not considered taxes or depreciation here).
In 2015, I consumed 1,800 kWh of electricity and fed in 34,000 kWh. I receive €0.16 for the kWh fed in.
I pay €0.31 per kWh including VAT.
My building has a heated area of just over 600 m² (6,458 sq ft), which would not be efficient to heat with a heat pump. Since I have a roof area of over 400 m² (4,306 sq ft) entirely facing south, it makes sense for me to install and use solar thermal and photovoltaic systems.
My heating system (Vaillant gas condensing boiler, 2,000 l (530 gallons) buffer tank, Vaillant solar station) cost around €12,000.
This means I have about €8,000 less investment than your heating system. For that, I get around 100 rm (stere) of wood.
Regarding the wood: 1 rm (stere) of beech wood currently costs about €80. 1 rm (approximately 550 kg / 1,213 lbs) of wood corresponds to a heating output of 2,000 kWh, which results in about €0.045 per kWh.
Heating oil is around €0.50 per liter and has an energy content of 11 kWh, similar to gas.
Looking at the costs now, I do not make up the extra expenses for a heat pump, so my statement is quite accurate.
Similar topics