Vesa-Pekka Vainikka, Kari Kuisma
Finland is a country where ambient temperatures can drop down to as low as -40 C in winter whereas summer temperatures can peak at over +35 C. These conditions, combined with the nonexistence of domestic oil, gas and coal resources, have given the Finns a natural opportunity to develop sustainable energy solutions. In particular, Finland has been a front-runner for decades in the development of modern, energy efficient district heating and cooling (DHC) solutions, integrated with combined heat and power (CHP) production. For example, in Helsinki, over 90% of district heat is produced by CHP. Since the 1950’s Pöyry has been playing a vital role in developing these advanced CHP & DHC solutions, which have been later adapted in numerous other countries.
In most energy efficient solutions, including the one of Helsinki, the entire heat production and supply chain has been optimised.
Finland is the leading country in the world in terms of combined heat and power (CHP) generation. Almost 80 per cent of country’s district heat production is based on CHP generation. Correspondingly, one-third of electricity is obtained in CHP generation. No other country has such a great market share of CHP electricity. In the EU, combined heat and power generation amounts to only just over ten per cent of the total electricity production.
Pöyry is a leading designer and project manager of Combined Heat and Power plants for industries and communities in Finland and in Europe. Pöyry has designed over 8000 MW Combined Heat and Power capacity during the past 10 years only and this is why Pöyry has been ranked for several years in a row as the number one company in the field of engineering Combined Heat and Power Plants (Top 200 International Design Firms list, published annually in July by Engineering World Record).
“Our expertise covers particularly combined heat and power (CHP) plants for industrial and communities, be it based on gas-fired combined cycle power plants, solid fuel and especially biofuel-based power plants, diesel power, you name it,” says Vesa-Pekka Vainikka, Senior Vice President of Pöyry for District Heating and Cooling.
“Combining the CHP expertise with the DHC know-how we are able to implement the most energy efficient energy solutions considering the entire district heat supply chain from heat production to distribution and supply to the end consumers, Mr Vainikka continues. The typical concept of a modern district heat supply chain is presented in Figure 1.
“In Russia there is huge energy efficiency potential related to optimisation of the entire district heat supply chain, claims Mr Vainikka. Taking full advantage of this potential is technically quite possible, but would require substantial investments, especially for consumer substations”, Mr Vainikka continues.
Pöyry’s experiences from District heat reconstruction projects
Mr. Veli-Matti Kivistö (pictured in Figure 2), Project Manager and Senior Adviser in District Heating and Cooling (DHC) at Pöyry, has more than 25 years of experience in DHC, covering Pöyry’s major DHC projects all over the world. He emphasises that modern DH systems must be constructed and operated based on sound economic criteria, using standardised, technically proven, and high-quality solutions.
“Accordingly, investments shall be made based on an analysis of economic viability. The DH systems must be competitive compared with alternative heating methods, bearing in mind that the key issues to consider in design and operation are to provide heat to customers in all conditions and to maintain customer satisfaction,” Mr. Veli-Matti Kivistö emphasizes.
Mr Vainikka continues that Pöyry has participated in DHC projects for the improvement and development of energy supply systems, not only in several Finnish cities but also in Ukraine, Russia, Belarus, Kazakhstan, Mongolia, Bosnia and Herzegovina, Serbia, Estonia, Lithuania, Latvia, Hungary, Italy, Poland, Sweden, the UK, South Korea,
and China.
For example, in Seoul, South Korea Pöyry has a long history of cooperation with Korea District Heating Corporation (KDHC). KDHC is the owner and operator of the largest modern district heating and cooling system designed and constructed in accordance with the Western energy efficiency design principles. One of the major CHP plants in the Seoul DHC system, the Bundang Plant, is shown in Figure 3.
“Our district heating reconstruction assignments have included, for instance, the preparation of energy development plans, assistance in tendering and procurement processes, investment plans and financial assessments, project management, construction supervision, renovation of municipal heating systems, energy saving technologies and audits, studies on DHC, gas and steam distribution networks and environmental assessments,” Vainikka describes.
Mr. Vainikka continues that in most of the implemented DH reconstruction projects financing from various international organisations and financial institutions (such as EU, WB, IFC, EBRD and governmental agencies) has played an important role in making the projects happen.
The overall vision on DH reconstruction
Our criteria and approach to carry out the analysis and the recommendations for the minimum cost investment plan are based on the fundamentals briefly presented in this chapter.
Modernisation of a large DH system is a long-term process and requires considerable investments and technical know-how. Typically, technical, financial and institutional issues set limitations for the possible reconstruction actions. Based on Pöyry’s experience in Russia and other transition economy countries we have developed a methodology , which is proven to result in the minimum cost investment, both short term, and particularly for long term with optimised lifecycle costs (i.e. lowest annual costs considering both investment and operating costs). Quite simply, the key issue is to prioritise the available investment funds into the most feasible reconstruction components. According to our experience, the optimised lifecycle costs can be achieved in a typical DH reconstruction project by prioritising the reconstruction investments as follows:
» Individual building level heat substations (ITPs): Gradual closure of the open Domestic Hot Water System (DHW) – if applicable – by ITPs equipped with heat exchangers and control valves for both space heating and DHW preparation (ITPs). ITPs have heat meters enabling invoicing based on real measured consumption. Installation of ITPs is also a key in the reconstruction of systems where the closure of an open DHW system is already done, but where consumer installations for space heating are still hydraulically connected to the DH network. Further more, building level ITPs enable the removal of Central block heat exchanger stations (CTPs) and particularly 4-pipe distribution DH pipe networks with short technical life time and high O&M expenses.
» Pipes: Replacement of old and worn out DH network sections with new DH network sections applying high quality bonded pre-insulated technique allowing excellent protection against external corrosion and reduction of leaks and heat losses.
» Other: Reconstruction of pumps, water treatment, automation, remote control and monitoring equipment at production plants enabling variable flow operation and high quality treated DH water
The Introduction of ITP’s will allow hydraulic separation of consumers’ internal installations from the primary DH network and, respectively, the utilisation of purified DH water in the entire DH system. The internal corrosion of DH pipes decreases, and the anticipated average technical life time of the DH network increases significantly in parallel with the progress of the hydraulic separation. Without the closure of the open DHW system and the hydraulic separation the average technical life time of the DH network remains low. It should be pointed out that the share of the DH networks in reinvestment costs of heat transmission and distribution is estimated to be 70% – 80%. Currently, an average technical life time of more than 50 years is anticipated to be achieved in modern DH systems.
ITP’s and variable flow will enable more flexible, energy efficient and safe system operation from production to end customers. Customers equipped with ITPs will be capable of regulating their heat consumption, which results in savings in annual heat energy consumption. Furthermore, the quality and reliability of heat supply will eventually increase. Application of feasible standardised, technically proven high quality, but simple/cost efficient, solutions through transparent procurement process should be ensured, when rehabilitation measures with new ITPs are performed.
Reconstruction of District Heat systems in Russia – Will it happen?
It is no secret that in Russia there is a clear necessity to invest in DH reconstruction in order to improve the technical life time of the equipment, increase efficiency of operations (including CHP production) as well as to keep district heating competitive enough against other heating methods. For example, based on our experience, the annual water leaks (losses) of a Russian DH system are typically high, between 8 – 30 (or even more) times of the total water volume of the DH network, whereas the corresponding figure in a modern Nordic DH network is only 1.
Furthermore, if the DH network is not upgraded and modernized the end customers may choose to disconnect from this network entirely in favour of other heating methods such as gas boilers/electric heating.
Pöyry has been involved during the past few years in several district heating reconstruction developments in Russia. “It is evident that the saving potential on a national level is enormous – not just related to energy but also to potential savings related to water, investment and operation costs of district heating systems,” says
Mr Kivistö.
Several Russian District Heating companies have already seen the potential and have started implementing reconstructions of their district heating systems. One of these companies is OAO Fortum, for which Pöyry carried out District heating system studies in Chelyabinsk, Tyumen and Surgut from 2008 – 2011 (Figure 4). The studies consisted of hydraulic analysis and simulations of district heat networks and recommendations for further actions in terms of future investments and other improvement measures. In Chelyabinsk, Pöyry teamed up with its Russian engineering partner JSC Cotes for the renewal of the district heating pumping system at CHP-3. “We are currently working together in several CHP/DHC projects in Russia and Kazakhstan, for example in Chelyabinsk, Blagoveshensk and Astana (Figure 5) and our experiences when combining global technology know-how with local expertise have been very encouraging”, commented Mr. Dmitry Serant, CEO of JSC Cotes.
“The biggest obstacle for kicking-off the reconstruction projects in Russia is that the financial incentives and clear institutional guidelines are not yet there, either on the producer side nor on the consumer side and district heating is still considered as a side-product to electricity. A common ground needs to be found in terms of what needs upgrading and how to carry out these projects” says Mr Vainikka.
“But, it is clear that fundamental reconstruction of district heating systems will be needed in Russia in the future and it is not a question whether it will happen but when it will happen”, Mr Serant concludes.
