Find answers to the questions we’re frequently asked about

Harp Bio-Digesters

1. What’s the Harp Biodigesters capacity range?

We provide a diverse range of options to suit businesses of various sizes, ensuring that we can handle any volume of organic waste, from 1,000 to 50,000 litres per week.

2. How Harp Biodigesters work?

Harp Biodigesters utilise our proprietary biotechnology that convert food and other organic waste into a highly-valued, dry, safe and nutrient-rich soil product / biofertilizer in less than 24 hours.

3. How long does the process take in the digesters?

Our proprietary Biotechnology converts food and other organic waste into a highly-valued, dry, safe and nutrient-rich soil product / biofertilizer in less than 24hrs.

4. What types of waste can be used in Harp Biodigesters?

Harp Biodigesters can process various types of difficult waste material, including organic waste, food waste, agricultural waste, and more.

5. Can I add any biodegradable product in the Harp Biodigester?

We recommend adding only BPI Certified Compostables. These products bear the BPI logo, ensuring they meet strict compostability standards and are designed to break down effectively in our biodigester. Not all biodegradable items meet these criteria for proper breakdown and compostability.

6. What happens if non-BPI Certified Compostables are introduced into the biodigester?

Non-certified compostable items might not break down efficiently or could cause disruptions in the biodigester’s operation. This could result in incomplete decomposition, slowing down the composting process or leading to issues within the biodigester.

7. Is water added to the biodigester?

No. Harp Biodigesters do not need any water supply.

8. Is the end-product of Harp Biodigesters a compost?

The end-product goes beyond compost. It is a high-value biofertilizer that is abundant in essential nutrients.

9. What to do with the end product?

You can either use it on your own grounds or a Harp representative will take it from you. Consult a Harp Renewables representative for advice

10. Is training available for using Harp Biodigesters?

Yes, Harp Biodigesters provides training to ensure proper usage and maintenance of the biodigesters.

11. Can Harp Biodigesters be installed inside or outside?

Harp Biodigesters can be installed both indoors and outdoors, depending on the available space and requirements.

12. Is information available regarding the carbon footprint of Harp Biodigesters?

Yes, information regarding the carbon footprint of Harp Biodigesters can be provided, showing the environmental benefits of the system.

13. Is there a lease option available for Harp Biodigesters?

Yes. Consult with Harp Representative to learn more about.

14. What are the end results when using different materials?

This will depend on the feedstock and the analysis required.

15. Is any liquid discharged from the biodigester?

Only small element of condensate.

16. Does Harp provide auxiliary equipment for use with their biodigesters?

Yes, Harp provides a range of auxiliary equipment to complement the biodigesters, enhancing their functionality and efficiency.

17. Where are Harp biodigesters manufactured?

Harp biodigesters are designed, developed and manufactured in Brownstown, Kentstown, Navan, Co. Meath, Ireland.

Biomass Boilers

1. What are the size ranges for Biomass installation?

Range from 47kw to 300kw but can go bigger by coupling.

2. What can your biomass applications cater for?

Hotels, schools, listed buildings, prisons, shopping complexes, swimming pools.

3. What are the advantages of using a biomass boiler?

Some advantages of biomass boilers include reduced greenhouse gas emissions, as biomass fuels are considered carbon-neutral, potential cost savings compared to fossil fuel-based boilers, utilization of renewable energy sources, and support for local economies through the use of locally sourced biomass fuels.

4. Can biomass boilers be integrated with existing heating systems?

Yes, biomass boilers can be integrated with existing heating systems, allowing for the retrofitting of biomass technology into buildings with conventional heating systems.

Harp Home Composters

1. Where can I get my Harp Home Composter?

Easily access all the information you need about Harp Home Composter on our user-friendly website, where hassle-free purchasing is guaranteed.

2. How does Harp Home Composter work?

It’s a plug and play machine , your Home Composter uses a mixture of heat, Harp enzymes and a stirring mechanism to help break down your food waste into an Organic compound.

  • It’s very simple, just open the packaging, add the special recipe Harp enzyme which we supply, just add 500 ml of water, switch it on, wait 24 hours, and effortlessly start filling it up with your food waste.
  • Begin with 700g for the first week and gradually increase to 1kg to 1.5kg per day, allowing for optimal composting efficiency.
  • Enjoy ample capacity. Harp Home Composter is perfectly suited for a family of eight, thanks to its spacious design.
3. Where can I put it?

The ideal location would be your garage, a garden shed or somewhere with easy access to a power point and some ventilation, while also ensuring protection from the elements.

4. Is there a smell from it?

Only a slight one, but if you use the deodoriser function on the machine it doesn’t last long. The smell only comes if the machine is heavily loaded at some point.

5. Does it make compost?

Oh Yes, and the very best of it, it has great N P +K numbers and has a Total Organic Carbon content of 52%

6. How much food waste can I put in?

After the initial slow feed for the first 2 to 3 weeks you can put up to 2 kg per day (this needs to be done in 2/3 separate feeds) and up to a maximum of 10kg per week.

7. Where can I use my compost? can I use it on plants and flowers?

You can utilize compost by incorporating it into the soil of flowerpots, established plants, and trees, as well as spreading it on that patch of lawn that’s not doing so well; however, caution is necessary due to its nutrient-rich composition, so a recommended ratio of 9 parts soil to 1 part compost ensures safe and efficient growth rates, and additionally, you can dilute the fine compost in a watering can to nourish your plants during the summer, providing cost savings compared to artificial growth stimulants.

8. How much energy does it use?

It uses about 1.5 kwh’s per day, very similar to a small fridge.

9. What are the benefits of using it?

By incorporating compost into your gardening practices, you not only experience various economic and social benefits but also contribute to the fight against greenhouse gases and help close the loop to get nutrients back into the soil, effectively turning your waste into fertilizer for a happier and healthier garden; moreover, this conscious approach towards food wastage helps prevent waste, leading to cost savings, while also reducing the amount of food waste in your black bin, resulting in weight reduction of up to 20 kg over a two-week period and saving you money on pay-by-weight bin charges.

10. What can I put in it?

You can put all types of food waste into it, peelings, leftover food, raw food, cooked food, food that has gone off. Just remember that it breaks down easier if you cut it up into thumb size particles, especially hard veg like carrots, turnip, broccoli stalks etc.

11. What can I NOT put in it?

Do not put any packaging, bones, cutlery, biodegradable bags, medicines, shellfish, paper towels, cigarette buts, fish bones.

12. How do I empty it, where can I store my fertilizer?

It’s simple, just wait until the compost is up to the max line and try not to put any more food in for 24/48 hrs, you then take the scoop supplied and just scoop out and store in an airtight container, then its ready to fertilise your garden and plants. Happy Gardening!!!!!!

13. I don’t have a big garden, what do I do with my extra fertilizer?

Don’t worry, we have that covered for you, just email us at and we will sort that out for you.

14. How long does delivery take?

Working with our partners DPD we offer next day delivery to the republic of Ireland and 2-to-3 day delivery to the North of Ireland and the UK. Mainland Europe will take a few days longer, but we will get it to you hassle free.

15. What if I am away for 2 to 3 weeks holidays?

Make sure machine is in about half full, press dehumidifier button to dry out any remaining dampness. Unplug machine and make sure the door is fully closed while your away. Just plug back in when you get home and run for 24 hrs before adding any food waste.

16. Is it a safe product to use?

Yes, it’s safe to use in the garden and safe around Children and pets.

It is not intended for human consumption.

Harp Renewables